PowerPoint Hangs in Open Box

When I attempt to open a file in PowerPoint 2000 using File-->Open, Powerpoint hangs in the dialog box. I've downloaded the updates that Microsoft suggests, but they were of no help. Any suggestions?

 

For anyone who is looking for the solution to this, I actually found it myself. http://support.microsoft.com/default.aspx?scid=kb;en-us;236872 is the knowledge base article that describes which entry to delete in the registry. I used Method 2 so I didn't have to erase all of the user settings. Thanks to anyone who tried to help!!