FYI - to all, thank you.

I backed up all my data, uninstalled IE 7.0, and then did a reinstall of
Windows XP. I lost virtually nothing and OE now works.

I suspect strongly that IE 7.0 is the problem.

I have switched to Mozilla Firefox and won't use internet explorer any more.
It has always been a problem here and there, but this was the last straw.

Thanks again for the help.