I understand you cannot find the outlook.pst file. Please continue this discussion
in the forum rather than by email :-)
How are you trying to find it ? It should be somewhere like:
C:\Documents and Settings\[username]\Local Settings\Application Data\Microsoft\Outlook\Outlook.pst
You may have to look in hidden files as somewhere in its path there's a hidden folder.
If it really doesn't exist then something's seriously wrong with your Outlook
installation (it creates one at startup if its missing) and yo umay have to uninstall/reinstall
it.
Did you try Outlook's Safe Mode ?