XP Media Center 2005 and WMP 11

I've just completed a new PC and installed XP Media Center 2005. I went to the Microsoft website and installed all available updates--even non critical ones.

My problem is that when I try to install WMP 11 I receive the "OS not recognized" error and directions to download Rollup 2 from the Microsoft website. However, this download is not listed on the update website as needing to be installed. I'm also certain it's not installed after checking the installed update list on Add/Remove software.

After trying to update with Windows Update several times, I attempted to use the third disc (called XP Media Center 2005 Updates) to see if there was something else needing to be installed. When I attempt to extract the files, I receive this error: .NET Framework 1.1 and .NET Framework 1.1 SP1 must be installed before you can continue with the update to Windows XP Media Center Ed 2005. Please go to the Windows UPdate to install the required software then try again."

Another visit to Windows Update just informs me that I do not require any updates.

Any suggestions would be a huge help.

Thanks!