Don’t know if this will help, but my son had similar problem.

He had a Word file, downloaded it, clicked on it, would not open, eventually locked up computer.

He was using W2k and Office 2000.

What was happening is Word Pad tried to open it, could not, but continued to use all the resources in the background so when he used Office to open it, it locked. Just used task manager to close the Word Pad application and opened it directly from Office, no problems.

Hope this helps.