For excel, I like to unregister first, then re-register.

Close Excel and
Windows Start Button|Run
excel /unregserver
then
Windows Start Button|Run
excel /regserver

I'll let someone else answer for PPT.

If this doesn't help in Excel, post back with some more details. I bet someone
will jump in with a suggestion (or a solution!).

Grad School Mom wrote:

I recently installed Office Student & Teacher Edition and have been unable to
get documents to save in the programs [Excel, PowerPoint, Word]. I did
finally get the Word docs to save correctly [not as a Wordpad doc] by
entering "winword /r" at the run command, which re-registered the Word
software. Does anyone know what command to use for re-registering Excel and
PowerPoint?

--

Dave Peterson