Sidestory, I was in the process of setting up a second Exchange 2010 server for DAG support, when I realized that my box needed Windows 2008 Enterprise edition. The box currently has

Windows 2008 Standard
Windows update including SP2
Exchange 2010 with CAS, HT, Mailbox roles
Domain Services role
File Services role.

When I try to upgrade to Windows 2008 Enterprise, I initially got a "your current version of windows is more recent than the intallation media", something to that effect. My first guess was it may be SP2 related, so I uninstalled SP2, restarted and tried again. This time it gave me an error to the effect

Windows could not configure one or more windows components. Please restart and try the update again.

This was at the last stage of the Windows 2008 Enterprise install when it says "Completing installation". So I removed Domain Services role (including demoting it as a DC). However I get the same error again.

Anyone see something like this before and have any suggestions? Also , is there a log file the windows upgrade program spits out that I can consult to see what component exactly is interfering?

Update 1 Based on some googling I finally found the setup log file, and it seems that Windows setup had an issue determining the .Net 3.0 "feature" being installed or uninstalled. So based of of a win7/vista technet article I'm going to retry the upgrade after removing the .Net 3.0 feature.