Repair Install

What is the exact procedure if any to do a repair install on XP pro. There is no backups the ASR hasn’t been run and no restore points. If there is such a thing as a repair install will it replace all of XP’s files and leave everything else in tact? I’ve had a network problem that I posted a while ago that nobody has been able to help with; it is a strange problem that probably will never happen again. It wont accept ticks in Client for Microsotf Networks and File and print sharing for Microsoft Networks. Thanks