Word may be corrupt, there are options to fix this without re-installing XP. As for your old files, search for the ones you don't want and delete them.
With Word it may only require the Normal.dot to be renamed as it may have become corrupt. This would then reload a new Normal.dot and Word should then work correctly. You should find it here: c: / Documents and settings / <Username> / Application Data / Microsoft / Templates
To help clean your system, there are other options. Ccleaner or Ashampoo WinOptimizer will help clean your system.
Download Ccleaner if you click here
Download Ashampoo WinOptimizer if you click here Download at the right hand side of screen.