Terms in or and symbols, all show more details on demand:

• Hover your mouse over any, or any term to see an
• Click any term in to see a box (try now)
• Don't bother to close the window , just click back here to return
• This Session works equally well if you prefer to click for details.

 
We round up the for common Batch file problems. They're captured from our experience of answering thousands of Batch file questions in (if your own problem isn't covered, see our Batch Reference and Batch Course):

Click link for details	Brief description
Operating System	Batch Language syntax varies with Operating system
Window stays open	MS-DOS window doesn't close (or closes too soon)
Long File Names	"Quote" long file/folder names containing  Space s
Internal name error	Don't give a Batch file an command name
External name error	Don't give a Batch file an command name
Batch File Extension	Use .BAT (in 95/98/ME), and .CMD (in NT/2000/XP)
Plain text format	Batch files must be plain text files
Environment memory	Increase memory to fix out of environment problems
Invalid switch	Invalid switch - / or Invalid parameter - / messages
Missing parameter(s)	Add any parameters, or use a  ?  parameter pop-up box
Delays and waits	Need to delay or wait? Our Batch Reference shows how
ECHO.{demo}	Commands ed for demonstration in our examples
MS-DOS window crash	Pop-up message: illegal operation, Batch file halts
Wrapped/missed lines	Cut-and-paste all text correctly
Third-party utilities	We regard SED, GAWK, and 4Dos as standard extras
MS-DOS Window	Real-mode syntax may be different or restricted
Batch Links	Up-to-date Web links for Batch resources

 
Don't forget that you can see extra information on demand:

• Hover your mouse over any, or any term to see an
• Click any term in to see a box with details and examples

We state what operating system our Batch scripts are written for (it's usually Windows 95/98/ME). They'll typically need some changes to work, in say Windows , where the more advanced Batch syntax of often allows simpler solutions.

 NT/2000/XP  The microsoft.public.win2000.cmdprompt.admin and alt.msdos.batch.nt specialise in detailed Windows NT/2000/XP discussions.

If you use an unsuitable script in Windows , error messages may include:

• ... was unexpected at this time.
• ... is not recognized as an internal or external command, operable program or batch file.

 
Don't forget that you can see extra information on demand:

• Hover your mouse over any, or any term to see an
• Click any term in to see a box with details and examples

If you want to run your Batch files by clicking on them in Windows Explorer, you may prefer that the (or ) closes as soon as the script finishes.

However, Windows normally gives you a chance to read any text left on screen by not closing the automatically. So, to make sure it does close, you need to make sure there's no text left on screen. You can do this by:

• Starting your Batch file with OFF
• Making (Clear Screen) the final instruction, like this:

The needn't literally be the last instruction. For example, this uses a followed by a the end of the code, so is the last instruction that affects the screen.

It's important that command is OFF when the is executed, so if you have ON (for debugging), remember to include an extra @ECHO OFF as shown.

The will close automatically as soon as either example finishes.

 Note  Learn how to write Batch Subroutines with a StudyPack from our Batch Library.

In rare cases, it may be necessary to add an command after the .

In Windows 95/98, you can load ANSI.SYS from CONFIG.SYS, then use ANSI Escape sequences for colours, with say, the command, as in this :

A command would clear the entire screen to the current background colour     . This has a similar effect to text left on screen - the window doesn't close automatically.

To have the close itself, clear the background colour like this:

• Set a colour-clearing : PROMPT $e[m (sets default Light Grey on Black)
• Force to ON with: ECHO ON so this will be displayed
• Insert a Blank Line (highlighted) to display , clearing all colours
• Finally, add @ECHO OFF and CLS as before

 Note 1  The Blank Line in the code is important, don't forget it.

 Note 2  Windows ME can't use ANSI.SYS (except from its emergency boot disk), so this problem shouldn't arise. For more details, see Microsoft Knowledge Base.

Sometimes, the reverse problem occurs: you want the to stay open, but it closes. In this case, you can use a command to halt the Batch file:

 Note  The of output to the : PAUSE>NUL allows you to replace the default message with your own, using an command.

 
Don't forget that you can see extra information on demand:

• Hover your mouse over any, or any term to see an
• Click any term in to see a box with details and examples

Long file or folder names that contain  Space s must be enclosed in "double-quotes" when used in Batch commands. If you don't do this, each fragment of the file or folder name is treated as a separate parameter. You also need to "quote" any long file or folder names passed as command-line parameters, for example:

       %0 (batch name) %1 (1st parameter) %2 (2nd parameter)  
C:\CSW>MyBatchFile.bat "C:\Program files" "C:\CSW\My File.txt"

Also applies to immediate mode (and scripted) Batch operations, for example:

ftp> put "File name one.txt"

When you expand environment variables in command lines, they must also be "quoted" if they may contain long file or folder names or with  Space s, for example:

xcopy "%SRC%\*.*" "%DEST%\*.*" /s /y

For more details of how works, use: xcopy /? | more at the , and click anywhere in this Session or in our Batch Course.

 Remember  Our Course Reference supplements the /? help, it doesn't replace it. In xcopy /? | more the to lets you read /? help one screenful at a time.

If you fail to "quote" Long file or folder names, you'll see error messages such as:

• File not found
• Too many parameters
• Invalid number of parameters

 
Don't forget that you can see extra information on demand:

• Hover your mouse over any, or any term to see an
• Click any term in to see a box with details and examples

The command processor that Batch files, ( or ) has the program code for commands. These commands take precedence over Batch files; don't use Batch file names that conflict with them. This example shows what happens if you name a Batch file ECHO.BAT and try to run it:

 Note  Even using the full name, ECHO.BAT, simply generates an (of bat). Using the full to the file C:\CSW\ECHO.BAT does run the Batch file, however.

If you use an command as a Batch file name, you'll meet problems such as:

• Bad command or filename
• Syntax error
• (various other error messages from the conflicting command)
• Output from the command instead of from your Batch file
• Your Batch file refuses to execute

Treat the Windows 95/98/ME commands as reserved names that you don't use for Batch file names. The list of reserved command names to avoid is as follows:

BREAK, CALL, CD, CHCP, CHDIR, CLS, COPY, CTTY, DATE, DEL, DIR, ECHO, ERASE, EXIT, FOR, GOTO, IF, LFNFOR, LH, LOADHIGH, LOCK, MD, MKDIR, PATH, PAUSE, PROMPT, RD, REM, REN, RENAME, RMDIR, SET, SHIFT, TIME, TRUENAME, TYPE, UNLOCK, VER, VERIFY, and VOL.

To find out what any of the commands do, read the CommandName /? help.

Some are obsolete or rarely used (eg ), or are used only at boot-time.

 
Don't forget that you can see extra information on demand:

• Hover your mouse over any, or any term to see an
• Click any term in to see a box with details and examples

commands are standard executable files in your system that the Batch Language relies on; don't use Batch file names that conflict with them. Problems will be most evident when a Batch file tries to use an command it shares a name with.

If you use an command name, for example FIND.BAT (which will conflict with the command), you'll meet problems such as:

• ... Required parameter missing
• (various other error messages from the conflicting command)
• Your Batch file restarts itself unexpectedly
• Your Batch file loops indefinitely
• Other Batch files fail to operate (and invoke the conflicting file instead)

Treat the Windows 95/98/ME commands as reserved names that you don't use for Batch file names. The list of reserved command names to avoid is as follows:

attrib, chkdsk, choice, cscript, debug, deltree, diskcopy, doskey, edit, extract, fc, fdisk, find, format, keyb, label, mem, mode, more, move, mscdex, nlsfunc, scandisk, sort, start, subst, sys, xcopy, and xcopy32 (component of ).

To find out what any of the commands do, read the CommandName /? help.

Avoid Batch file names that conflict with TCP/IP commands: ftp, ping, tracert. For examples using scripted from a Batch file, see our Batch Library. Be alert for conflicts with any other executable names in your system .

 
Don't forget that you can see extra information on demand:

• Hover your mouse over any, or any term to see an
• Click any term in to see a box with details and examples

Batch files in Windows 95/98/ME are by , and should have a .BAT file extension. Batch files in Windows are normally by , and may have extension .BAT or .CMD (use .BAT if the Batch file is written to run on Windows 95/98/ME as well as Windows ).

 Note  Windows has a version of for legacy use, but it has fewer features than and is better avoided.

Take care saving Batch files with Notepad. If you save Notepad files carelessly, you may add a spurious .TXT extension. Use Save as type = All Files (*.*).

If you use the wrong extension for Batch files, you'll usually see the error message:

• Bad command or filename (in Windows 95/98/ME)
• ... is not recognized as an internal or external command, operable program or batch file (in Windows )

 
Don't forget that you can see extra information on demand:

• Hover your mouse over any, or any term to see an
• Click any term in to see a box with details and examples

A Batch file must be a plain text file. Write them with a text editor such as Windows Notepad (use Save as type = All Files (*.*) to avoid a spurious .TXT extension). If you use a WordProcessor, such as WordPad, Save as type = Text Document.

If you save a Batch file as a WordProcessor document, you'll meet problems such as:

• Bad command or filename
• Lines of strange characters displayed on screen
• Multiple system beeps

Some specialised editors, such as TextPad, have Batch syntax highlighting, thus:

 Note 1  The example uses to compare two text files whose names are passed as command line parameters, %1 and %2, after checking the files exist. The highlighting is user-configurable: we highlight s and our standard labels, such as EOF, too.

 Note 2  In a practical version, if insufficient or non-existent parameters are supplied, you should generate an error message instead of merely skipping to the end of file.

Our Batch Course (Lesson 20) covers using s with to return s.

 
Don't forget that you can see extra information on demand:

• Hover your mouse over any, or any term to see an
• Click any term in to see a box with details and examples

Most Windows 95/98/ME Batch files use environment variables, which are stored in a region of memory reserved by . The default amount reserved is quite small (about 160 bytes), and if you work with Batch files you may want to increase it.

In Windows 95 or Windows 98, you can change the default environment memory by altering the file CONFIG.SYS in your root folder. To reserve 2048 bytes (adequate for most purposes) add the following two lines (the first is a comment) to CONFIG.SYS:

;2048 bytes environment space and 255 character command line
SHELL=C:\WINDOWS\command.com C:\WINDOWS /e:2048 /p /u:255

If you already have a SHELL= line in your CONFIG.SYS, you should add any changes to it, rather than add a second SHELL= line. Changes take effect at the next reboot.

In Windows Millennium, you can increase the default Environment with a setting in SYSTEM.INI (in your Windows folder) – for example, to set a default 2048 bytes:

1. Open C:\WINDOWS\SYSTEM.INI in Notepad
2. Find the section headed: [NonWindowsApps]
3. Add a new line below: CommandEnvSize=2048 and save the file again

In Windows 95/98/ME, you can change the environment memory allocated in a particular or in the Shortcut to a specific Batch file. Open the Properties dialogue (right-click the Shortcut or Desktop icon, and click Properties).

Click the Memory Tab. Use the initial environment pull-down box to set a size that's enough for your variables, say 2048 bytes (or more if you wish).

See Lesson 19 of our Batch File Course for full details of how to configure a Batch Shortcut in this way (with an interactive walk-through).

 NT/2000/XP  You don't need to do this in Windows , because reserves ample environment memory. If you receive out of environment messages, older software may be using the provided for backwards compatibility.

You can alter environment memory with the /e , for example:

command.com /e:2048 /c MyBatchFile.BAT

will run MyBatchFile.BAT in a with 2048 bytes environment memory. To read about other , use command.com /? (the /y debug-mode shell and the /z return-code shell are not available in Windows ).

If there isn't enough environment memory, characters may be lost from environment variables as they are truncated. You'll usually see the error message:

• Out of environment space
• Various other errors will result from characters lost in variables

 
Don't forget that you can see extra information on demand:

• Hover your mouse over any, or any term to see an
• Click any term in to see a box with details and examples

A Batch command may fail with an Invalid switch - / or Invalid parameter - / message:

In the example above, the answer is clear. Although the in the commands are correctly "quoted", the /d and the /x are indeed invalid.

For valid and , see the /? help: for example dir /? | more (the added to shows /? help one screenful at a time).

An Invalid switch / or Invalid parameter / may also arise from a bad network :

Here, and are being used with an incorrect network . Windows needs a backslash  \  separator in network . In the example, everything following the incorrect  /  is interpreted as an invalid . For an easy drag-and-drop method to find network correctly, see our Batch Reference

The correct network syntax for the and commands above is:

dir \\OTHER\C\DATA\*.* and xcopy \\OTHER\C\DATA\*.* C:\DATA\*.*

 
Don't forget that you can see extra information on demand:

• Hover your mouse over any, or any term to see an
• Click any term in to see a box with details and examples

Batch files are frequently written to use command-line parameters. These are text tokens added after the Batch file name, on the same command line, and are used in the Batch file as %1 (first parameter), %2 (second parameter), and so on through %9. Make sure you supply parameters (often file names or ) if a Batch file expects them:

MyBatchFile.bat "C:\My data\File One.ext" FileTwo.ext

 Note  The example checks for at least two command line parameters, and skips to the end of file if they aren't found (it's better to warn the user if parameters are missing). If you're unfamiliar with command-line parameters, see Lesson 12 of our Batch Course.

You can add command-line parameters in the Cmd-line field of the Program Tab of a Shortcut to the Batch file. If you use the special  ?  as the parameter in the Cmd-line field of a Shortcut, Windows displays an Input Box (each time the Shortcut is used) in which you type any required parameters.

See Lesson 19 of our Batch Course for more details of how to configure a Batch Shortcut in this way (you can see an explanation of each of the many fields in the Properties dialogue with the usual Windows click-drag-and-drop method).

With Batch files, it's better to test for valid parameters, and warn the user if they're missing. If you leave out the command-line parameters that a Batch file expects, you may meet these problems:

• Syntax error (if the Batch file didn't test for parameters properly)
• The Batch file may terminate immediately, without doing anything
•  Ideally  The Batch file will display Usage instructions specifying parameters

 
Don't forget that you can see extra information on demand:

• Hover your mouse over any, or any term to see an
• Click any term in to see a box with details and examples

Many Batch files carry out critical operations, such as deleting or renaming sets of files, or running powerful commands. Typically, a Batch file will calculate the command lines needed for these operations, and then execute them.

To allow you to see what a Batch file would do, but without actually doing it, we often write Batch files to the calculated commands. It can be confusing to see valid commands ed without executing, so we add a {demo}, too, after the .

For example, a command line to rename a file to the current date (which had been calculated in environment variables), might be built up in stages, eventually becoming:

:: Remove the ECHO.{demo} to activate command
ECHO.{demo}REN %3 %CY%%Y%-%MO%-%D%.*

Instead of executing the command on the file passed in %3 (say, FileName.EXT), the Batch file displays the command (expanding the variables) to show what would happen:

{demo}REN FileName.EXT .*

The {demo} reminds you that the command is merely being ed. When you are satisfied that the commands generated in this way will do exactly what you want, you can remove the ECHO.{demo} prefix from them. Then, the generated commands will execute (not simply with a {demo} warning) when the Batch file is run.

:: Rename command now active
REN %3 %CY%%Y%-%MO%-%D%.*

The above command isn't ed on screen, it's executed.

 Note  To create variables containing current date elements, see our Batch Library.

 
Don't forget that you can see extra information on demand:

• Hover your mouse over any, or any term to see an
• Click any term in to see a box with details and examples

Sometimes a Batch file crashes the (or ) in which it's running, and you see a pop-up window with an illegal operation message like this:

When you click the  Details>>  button in an actual case, you'll see a message such as:

• The program tried to execute an invalid instruction.
• and a hexadecimal fault location, such as 902B:007C.

The typical causes are:

• script failure: a small program overruns into a data segment
• Some apparently minor syntax errors (see example below):

The above example actually happened in developing one of the Batch files used to maintain this Website. The matching second  %  character needed to expand the variable YDAY is missing (and the crashed at 902B:007C). The correct coding is:

The correctly restored  %  character is highlighted - such mistakes are easy to make. You can diagnose these problems by inserting breakpoints with combinations of commands and ed messages (with paired ECHO ON and @ECHO OFF to display sections of Batch code at work). See Lessons 8, 9, and 10 of our Batch Course.

 
Don't forget that you can see extra information on demand:

• Hover your mouse over any, or any term to see an
• Click any term in to see a box with details and examples

If you cut-and-paste the text of a Batch file from one of our posts, make sure you include all the lines. And make sure none of the lines wrapped wrongly in your newsreader. We normally prefix all lines with two  Space s, so you can spot if lines have wrapped incorrectly. This simplified example shows correct and incorrect versions:

Correct version (each line begins with    = two  Space s:
====Begin cut-and-paste (omit this line)
  @ECHO OFF
  FOR %%F IN (C:\WORK\*.TXT) DO IF (%OK%)==(GoAhead) TYPE %%F

====End cut-and-paste (omit this line)

Wrong version (third line doesn't begin with    because second line has wrapped):
====Begin cut-and-paste (omit this line)
  @ECHO OFF
  FOR %%F IN (C:\WORK\*.TXT) DO IF (%OK%)==(GoAhead)
TYPE %%F

====End cut-and-paste (omit this line)

There's no need to prefix your own lines with  Space s in this way, it's simply a safeguard we adopt for posts of Batch file examples.

If lines are missing, you may see only a part of the output you expected. You may also see error messages such as:

• Label not found
• Bad command or filename
• ... is not recognized as an internal or external command, operable program or batch file (in Windows )

If lines are wrapped accidentally, you'll see error messages such as:

• Invalid number of parameters
• Bad command or filename
• Syntax error
• ... is not recognized as an internal or external command, operable program or batch file (in Windows )

 
Don't forget that you can see extra information on demand:

• Hover your mouse over any, or any term to see an
• Click any term in to see a box with details and examples

As far as possible, we avoid utilities. The main advantage of using the Batch Language is that it runs on any machine with the relevant operating system. If your Batch files can't run on a normal installation, you lose one of their key features.

However, a few utilities are worth learning to use because they are in fairly wide use, or perform functions that aren't feasible without them. But bear in mind that the more utilities you rely on, the less generally useful your Batch skills will be.

Our posts sometimes use one of these three (the SED and GAWK links are for the versions we use ourselves, and are not necessarily the most up-to-date ones):

• SED – (the Stream EDitor) – download SED
• GAWK – (GNU ) – download GAWK
• PV – (the PrcView process viewer/killer) – find PV here

The 4Dos is an alternative command processor for . It is intended to replace , and has a wide range of powerful Batch features. It used to be a commercial product, but from 24th August 2004 the Windows 95/98/ME version of 4Dos became free. You can download it from the 4Dos Website.

For those who want to try 4Dos now it's free, but are reluctant to go as far as replacing their standard , we've published Our 4Dos Guide. This explains how to install a set of 4Dos components in a Custom . Installed in this way, you can learn to use 4Dos without altering your Windows operating system.

If a Batch file can't find a utility it depends on, you'll see the error message:

• Bad command or file name (in Windows 95/98/ME)
• ... is not recognized as an internal or external command, operable program or batch file (in Windows )

 
Don't forget that you can see extra information on demand:

• Hover your mouse over any, or any term to see an
• Click any term in to see a box with details and examples

We normally write to run in an in the Windows . In an you can use many extra features: with Long File and Folder names; the command; and useful extra with commands such as .

We explain how to configure an that is ideal for running Batch files in the Introduction to our Batch File Course.

An unsuitable script run in (or a badly-configured window) may report:

• Invalid number of parameters
• Invalid parameter
• File not found
• Out of environment space
• This program cannot be run in DOS mode.

 
Remember, hover your mouse over any, or any term to see an

Our own interest was originally stimulated by the highly intuitive techniques developed by Tom Lavedas, whose Website is well worth studying. For general links, Frank-Peter Schultze keeps an up-to-date, detailed list of Batch Bookmarks that's very useful.

Newcomers to the Batch Language in Windows 95/98/ME can learn its syntax with our interactive, Web-Based Batch Course with built-in reference. When you've completed our Course, use our documented Batch Library and Batch Reference.

We've posted thousands of Batch file solutions to Usenet . You can search through our previous posts on Google (but not all posts are archived).

If you have Batch questions, or can't find an old post of ours, please . Your email subject line should contain: Allenware.com website. Please be sure to say whether you are using Windows 95/98/ME or Windows NT/2000/XP.