Windows XP Sluggishness

So I originally came here in help of what I thought was a virus/malware causing my computer to be sluggish and extremely slow (svchost.exe will rise to 75% every once in awhile out of nowhere and when the computer is on idle). After many attempts to find it, it turns out the computer was slow for reasons unexplainable (link to post below):

http://forums.majorgeeks.com/showthread.php?t=163681

Well, I was told to do the sfc /scannow to determine if there was anything missing from Windows XP that could have been related to the problem, and of course something popped up saying that it was missing some files necessary for Windows XP. Unforunately, I got my version of Windows XP online from Texas Tech, the school I go to. They don't have purchaseable cd's to repair/install, instead you have to download a package that wipes the computer clean and doesn't repair it. I was wondering if there was any program that could identify/locate the files that were missing, and determine what to do to fix them. I have too many files from classes and other things to effectively back up. Anyone have some ideas?

 

Yes, it does have to be the same....

You can check the PC for a folder called i386, it would be in the root directory or possibly on a recovery or 2nd partition on the hard drive. If you have it, burn it to a CD and it should work in place of a 'real' Windows XP disc for running sfc /scannow. If you don't have it, borrowing a CD is about your only option, or you can buy one....

 

Well, it has to be the same as the version that was installed.

IOW, if you installed XP SP1 and upgraded to SP3, an SP1 CD is fine, assuming you did not clear out the SP3 cached files.

 

Yea the i386 didn't work when i burned it to a cd. Is there perhaps a third party program that determines what is missing and what needs to be repaired/replaced.