When doing a save as, it freezes

I have a Dell Optiplex GS240 P4 256 memory 32 MB ATI graphics card plenty of h.d. Space running Windows 2000 SP2 Office 2000 SP2. When I’m in Outlook or any other Office suit application and I do a save as the whole computer freezes up. This does not happen all the time and it does not matter if I’m saving to the network or locally. Any suggestions would be greatly appreciated