Just browsing your post (since it's late and I really couldn't give you a good answer right now because I'm tired) you say ctfmon.exe was missing. Per the website Liutilities, ctfmon.exe is an application related to Office XP and has nothing to do with Windows XP itself.
http://www.liutilities.com/products/...ibrary/ctfmon/
If other files were missing as well I would dump all important files onto a CD and wipe the drive clean and reinstall the OS (not repair, but reinstall). That's just me though.