Office won't run for specific user

Hi there;

I have an XP Pro computer on a domain network. For some reason the Office
product stopped working for User A (the primary user of this computer). If
User B logs on (that would be me) Office works fine. Both users are local
admins.

When user A tries to run Office there are no windows popping up or dialog
boxes displayed. Just a brief appearance of the hourglass cursor. If I
have task manager running I will see the Office application appear in the
process list for a few seconds then disapppear.

The computer had Office 2003 on it when this began but I thought upgrading
to Office 2007 might cure the issue. I've tried removing and reinstalling
Office. I've removed User A's profile and recreated it but nothing seems to
work. I've run the Office diagnostics and I've done a repair from the
Add/Remove Programs.

Hopefully someone out there will have some ideas.

All comments and suggestions gratefully accepted.