excel; File Open or click on open folder

I can open up Excel and over to the right side of the
screen click on a document that exsits and open it but
when I go to do file open or just click on the open folder
Excel locks up and then I have to cntrl alt del to get to
task manager to end task. All other office products work.
Using Office XP. Have repaired, uninstalled, taken out of
registry, reinstalled, rebooted. The only way to get out
is end task and the only way to get to another file is
through my documents. Just short of format and don't want
to do that just for Excel. Please help.
Thanks.