Microsoft SQL Server 2005 Upgrade Advisor: Unkown Error

I been trying to get the Upgrade Advisor working on Windows 2003 R2 SP2. But every time it keeps erroring out when it is about to start analyzing.

All it returns is “ERROR” in the status screen with no report; no explanation on why it failed.

I decided to look to see if there is a error log file or such generated with no luck. When you look at the download link for SQL Server 2005 Upgrade Advisor (Link); the requirements state that it works for Windows 2003 SP1 and needs .NET 2.0. I can’t uninstall SP2 from the OS; but when I looked at the Add/Remove I saw we had .NET 2.0 SP2, .NET 3.0 SP2, and .NET 3.5 SP1 installed. So I thought the 3.0 and 3.5 versions maybe are causing the issue? I uninstalled it but is still refuses to work. I then uninstalled .NET 2.0 SP2 also and installed .NET 2.0 (Link).

Hold and behold it starts working on Windows 2003 R2 SP2. But on my personal computer with Windows XP SP2 .NET 2.0 SP1 and .NET 3.0 (needed for SQL Nexus) the Upgrade Advisor works fine.

Conclusion

Problem: Microsoft SQL Server 2005 Upgrade Advisor fails for unknown reason on Windows 2003 SP2.
Resolution: Uninstall all .NET versions and install .NET 2.0 (without SP).