Compatibility and Version Problems
Installing Office 2010 under Windows XP 64-bit
In the first place, Microsoft wanted not to support Windows XP for Office 2010 installation at all. Thanks to heavy pressure of the WinXP user community, they are supporting Windows XP 32-bit (for one last time). But WinXP 64-bit, any service pack, is still unsupported. Yet it is possible to get Office 2010 running.
First, the setup needs to be tricked into thinking SP3 was installed (there's only a 64-bit SP2, although having the functionality of 32-bit SP3 it comes with the version number of 2). That can be done with Microsoft's Application Verifier tool (for anyone who knew DOS: it's kind of a SETVER.EXE for Windows) – Information Download.
Note that AppVerifier requires administrative rights.
Second, the compatibility mode for "Windows XP" needs to be set on the shortcuts to Word, Excel, Powerpoint (maybe others, too). Outlook runs fine without compatibility mode. This is done in the Properties (click right mouse button on start menu shurtcut of each program).
Accessing Windows 2000 Server from Windows 7
Symptoms: When trying to "NET USE \\win2000server" from a Windows 7 computer, you will get an "username or password incorrect" error message although the data IS correct.
Solution: Open "secpol.msc", "Local Policies" / "Security Options" – "Network Security: LAN Manager authentication level" and set to "Send NTLMv1 responses only"