Over the past few months I started to get the same error message when
I start up Outlook, (I have Outlook 2007, 12.0.6562.5003 SP2 MSO,
running onWindows 7).

I try to open Outlook and I get the message:
"Can not start Microsoft Outlook a program error occured. Quit
Outlook and Microsoft Windows and start again".

I've been running Scanpst.exe, and apparently it's repairing
somehting, but usually, Outlook won't start until I restart my
computer.
Another thing that's a started at the same time is that when I do
re-start, the re-start hangs up with the message that it's waiting for
Outlook (which never opened!) to close. I have to force the re-start
or it hangs up forever.

As usual, helpful input is appreciated.