If you use Windows Server 2003 with Service Pack 2 like a workstation (as described in many nice tutorials like this) you can be quite sure that all applications designed for Windows XP could run without problems.

However there is a number of applications which refuse to install as designed for Windows XP with Service Pack 2 or later. A similar problem also exists with application which refuse to install over Winsrv2k3 on a x64 platform, while they would install without any problems on WinXP x64.

You can try to trick out these install programs by using a little utility called Application Verifier by Microsoft. Just download and install the correct version (if unsure, choose ApplicationVerifier.x86.msi).

Once installed, do as follows:

1. Start Application Verifier;
2. Go to File then Add Application (or press CTRL+A);
3. Choose the .exe file that you want to trick (eg. setup.exe);
4. From the Tests pane on the right, deselect all items;
5. Expand Compatibility and tick HighVersionLie;
6. Right-click on HighVersionLie and select Properties;
7. Put the following values then press OK:
   
   • Major version: 5
   • Minor version: 1
   • Build number: 2600
   • Service pack major: 2
   • Service pack minor: 1
   • Suite mask: 0
   • Product type: 1
   • CSD version: (leave empty)
8. Click on Save;
9. While Application Verifier is still running, start the application.

When the application will call the GetVersion of GetVersionEx API function, it will return the fake values (in this case 5.1.2600 SP2.1, ie. Windows XP Professional SP2).

This works without problems for Adobe Photoshop CS3 setup program, as described in this article. Some other programs may use additional checks, such as AVG Antivirus, and hence they won't work anyway.

For further details on parameters you could use to fake other Windows versions and/or platforms, please refer to OSVERSIONINFOEX structure on this MSDN article.