Please help, XPCOM error

Hey, my computer has been acting up recently, so I have been thinking about reformatting, but i think i found out what is causing the problem when i went to shut down my computer last night, it came up with an error, cannot end program XPCOM, well, i didnt know what it was, so i did a search for it on my computer, and all it found were 3 .dll files all with XPCOM in the name: location, C:/program Files/Mozilla Firefox. Now that really puzzeld me, so well, I tried to do a Windows Repair with the Windows CD (XP Pro) but it came up with several errors during installation and was unable to continue, so now im on my trusty laptop while its reformatting. Does anybody know what that program is and what it does, is it somekind of virus? Thanks so much for any and all help!

bump, still would like some help..........

Please post a hijackthis log so we can see whats going on

oldmx