Lie to incompatible programs


There are programs which will not install or will not run well except under Windows NT or Windows 95. This can really be a pain when that stupid *** program won’t install and we are running on a newer more functional version. Windows 2000 and Windows XP includes the Application Compatibility tool, apcompat.exe, which is a tool that lies to programs that perform compliance checking in Windows 2000. Its very helpful for Win9x games that are written to run only under Win9x because of DirectX issues. Windows 2000 includes DirectX 7.0; Windows NT 4.0 includes DirectX 3.0. It fools the program about where it is running. It does not make the program compatible with Windows 2000 if it was written to directly access hardware or use virtual device drivers (VXDs)which are not supported by Windows NT or Windows 2000. For more information on apcompat, see: Q251062 Description of the Application Compatibility Tool.

SP2 for W2K introduced a method particularly useful for setting compatibility mode. This capability was built into Windows XP. The option is disabled by default. To enable in W2K or XP, when logged in as an administrator:


  • Click Start
  • Click Run
  • Type cmd
  • cd %systemroot%\AppPatch
  • regsvr32 slayerui.dll

When you press Enter, a successful installation generates the message:

DllRegisterServer in c:\winnt\appatch\slayerui.dll succeeded

To disable compatibility mode:


  • Click Start
  • Click Run
  • Type cmd
  • cd %systemroot%\AppPatch
  • regsvr32 /u slayerui.dll

Different from the Windows 95 MKCOMPAT, the Windows 2000 compatability mode option only operates as a shortcut. Now you can right-click any shortcut on the desktop and select Properties. After running regsvr32, there is now a Compatibility tab. For any application you want to run in compatibility mode:


  • Create a shortcut to the application and place the shortcut on the desktop.
  • Right-click the shortcut and click properties.
  • Select the compatibility tab
  • Check the Run in compatability mode checkbox
  • Select the OS you want to the application to think it is running under:

    • Windows 95 Compatibility Layer
    • Windows NT SP5 Compatibility Layer

If apcompat is not adequate, and remember it doesn’t alter the program, it only lies about certain issues, then you can try Replendent Resolver which lies to incompatible programs about your operating system, CD-ROM and disk drives, screen resolution, memory status, installed processors, volume serial numbers, current date and time and more so that they lose their unreasonable built-in protection. Replendent Resolver is shareware for Windows NT and Windows 2000.

Microsoft’s DirectX Home Page

As an aside DirectX 3.0 is only version supported by Windows NT and DirectX 7 or later is supported by Win9x, W2K, …

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