Do Not Use the MS-DOS APPEND Utility in Windows

The information in this article applies to:

• Microsoft Windows Software Development Kit (SDK) for Windows versions 3.1 and 3.0

SUMMARY

The MS-DOS APPEND utility remaps the contents of specified directories into the current directory, which makes the files of these directories available to an application. Do not use this utility on systems running the Windows operating environment because the APPEND utility is fundamentally hostile to the operation of Windows. The design of Windows rests on its ability to build a fully-qualified path for each file it opens.

MORE INFORMATION

When Windows opens an application file (for example, WINWORD.EXE), it stores the fully-qualified path of this file (for example, D:\WINWORD\WINWORD.EXE). With this information, Windows can reopen the file even if user or application activity changes the current drive and current directory.

The problem with the APPEND utility is that it prevents Windows from reliably determining the proper fully-qualified path to a file. If an application calls the open function when C:\EXCEL is the current drive and directory, and the D:\WINWORD directory is specified in the APPEND search path, Windows may improperly record the fully-qualified path to the WINWORD.EXE file as follows: C:\EXCEL\WINWORD.EXE.

In this situation, when Windows reopens the file later, it receives an error from MS-DOS because the file is not actually located in the drive and directory indicated by the stored fully-qualified path. When Windows detects this error, it displays the Change Disk message box.

The APPEND utility can cause similar problems for the WINOLDAP module, which runs MS-DOS (non-Windows) applications under Windows. These problems can result in unexpected "File Not Found" errors, failure to start an MS-DOS-based application, failure when the MS-DOS-based application exits, or failure when the user tries to switch back to Windows.

The current versions of all the major application software available today do not require the APPEND utility. The MS-DOS version 4.0 and 4.01 installation programs usually add the APPEND utility to the user's configuration, which consumes valuable application memory without providing any benefits to the end user. The APPEND utility is usually found in the AUTOEXEC.BAT file. The line with APPEND can be removed or commented out by placing the word "remark" at the beginning of the line.