xp-pro programs corrupted (add-ins ?)

Just loading up a new desktop pc with programs I had on my old pc.
Two programs which worked ok and then next day were corrupted.

The first one (Toolkit 5) had files in it's directory from MS Office. Deleated and reinstalled and worked ok.

The 2nd one (Office 2003) Excel & Word worked ok when installed but the next day Word was ok but Excel is corrupted with Word .doc files.

How do I stop the add-in files?

My system is xp-pro sp2,
MB Asus 5PK,
CPU Intel Core Duo (Penryn) 3.0 Ghz 6mb Cache
Video Asus GeForce 8800 GT, 512 mb

This is a dualboot system with Vista Home Premium

 

It sounds like the install of Office 2003 went astray somehow. Uninstall it and reinstall while in safe mode.