PC would not start up yesterday. Worked on it till it finally booted but some features would not work (wireless network, external hard drive, etc.). Trying to access things like My Network Places or device manager results in a blank window. Attempting to start services in management console results in error message saying "The plug and play service or another required service is not available."

Other things like trying to restore to an earlier time do not work.

I am running an HP desktop with windows media center, win xp sp2

Can anyone help?

Unable to correct problem. Decided to to use recovery console and installed so-called nondestructive recovery.
System is now functional except it cannot connect to the internet and many of the non-bundled applications no longer work.

I will mark this post solved but it really isn't, yet.