The repair tool is not located within Outlook. The repair tool is called
scanpst.exe. You can do a file/folder search for it but you must use the
Advanced options so that you can choose to search hidden files/folders.
Once you locate scanpst.exe, double-click it to open it and then follow the
prompts. It will ask you where your PST is located so you must know this
information.
If scanpst.exe finds errors and repairs them, run it again. Repeat until no
errors are found, then try opening Outlook.
If you're using an older version of Outlook or you brought over your PST
from an older version of Outlook (2002 or earlier), please verify the size
of your PST. Since the older versions of Outlook have a size limit of 2 GB
(but often become flakey or corrupt by approximately 1.6 GB or so), you may
have to compact the file. If the PST is an older version and exceeds the 2
GB limit, please post back.