Search Companion Problem

Attempted to reinstall srchasst.inf and need to reinstall msgr3.dll in order to reinstall seach companion…I did attempt to use the recover drive but that proves to be unusable for this problem.

Need to reinstall M/S Windows XP, but XP was preinstalled. How can I reinstall the msgr3en.dll and srchasst.inf files, or, Win XP if necessary, without repurchasing the software, and don’t know anyone who has the software on CD.