Before you do that, do you have a checkpoint that you can restore from? Go to
Start > Help and Support and under Pick a Task look for "Undo changes to your
computer with Sytem Restore". Check "Restore my computer to an earlier time"
and then click on Next. A calendar will appear. There probably isn't a
checkpoint created for 11/24, so click on Tuesday (11/23). Pick the first one
you find and then click on Next. The system will go through a process that
includes restarting. Don't touch anything until you see a message that says
that the restore was a success. Read the message carefully because sometimes
the restore cannot be done.
When that finishes try opening PowerPoint. Has the problem gone away? If not
you'll want to try the next available checkpoint, going backwards in time. You
may be able to get PowerPoint working again this way. It all depends on when
this problem was introduced to your system. If that doesn't work, you can try
uninstalling Office 2003, but that should be the last resort because most likely
it will not clean out the problem.