Windows 2000 tries to ensure compatibility with applications written for older versions of Microsoft Windows (Ex. Win95,Win98,WinNT4). Many application performs a version check of the operating system to ensure they will be able to work properly. Windows 2000 can trick such an application into thinking that it is being executed on an older version of Windows.

Microsoft have already created profiles for many old applications, so they will work out of the box with Windows 2000. The administrator can with Windows 2000 Service Pack 2 create own profiles for applications which requires Application Compatibility-Mode.

To activate the Application Compatibility-Mode interface (When activated a "Compatibility"-tab will appear when selecting Properties for a shortcut):

regsvr32 %systemroot%\apppatch\slayerui.dll

To deactivate the Application Compatibility-Mode interface:

regsvr32 /u %systemroot%\apppatch\slayerui.dll

More info MS KB251062
More info MS KB279792

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