Please make sure that you have your SQL Server & IIS Installed. (I tested on SQL Server 2008 SP1 & IIS 7.5)
1. Download Setup Helper
2. Run the setup helper (WssVista.msi)
3. Run “gpedit.msc”
   
4. Go to Computer Configuration –> Administrative Templates
    –> Windows Components –> Application Compability
    –> Turn off Application Compatibility Engine –> Set to Enabled!
   
5. Go to C:\Program Files\WssOnVista\Setup
   
6. Run SetupLauncher.exe
7. Browser your SharePoint Server 2007 or WSS 3.0 setup file (OfficeServer.exe or SharePoint.exe)
8. Remember to disabled Turn off Application Compatibility Engine
9. Remember to Install the latest service pack (SP2) for SharePoint Server 2007 or WSS 3.0
10. YES!, You’ll be happy to see this … running on your Windows 7