- Close Outlook -- likely it's already closed, because if the PST file is corrupt, Outlook wont run.
- Find the Command Prompt, right-click, and run as Administrator.
- At the command prompt, enter "C:\Program Files\Microsoft Office\Office12\SCANPST.EXE", including the quotes. If you have a different version of Outlook, you may still have a repair program -- find it and replace with the string I have here.
- When prompted to Repair, select Repair.
- Enter 'Exit" at the command prompt to close the Command Prompt window, and run Outlook again.
Some folks may not have an Admin password for Vista. If that's the case, check out these instructions for further help.