Thank you.
Try repairing the Personal Folders (.pst file)
How to use the Inbox Repair Tools
You may need to enable:
Show Hidden Files and Folders.
For Windows XP:- Open My Computer or Windows Explorer
Tools > Folder Options > View tab,
under Hidden Files and Folders, verify Show Hidden Files and Folders is selected.
Remove the check mark for:
Hide Extensions for known file types
Apply, OK to save and close.
Do a Search for:
scanpst.exe
Check in this folder first:
C:\Program Files\Microsoft Office 2007\Office12
Check in this folder for your .pst files:
C:\Documents and Settings\User Account\Local Settings\Application Data\Microsoft\Outlook
Or,
Control Panel > Mail icon > Data Files > Open Folder should get you there.
Using the steps in the link above, run the
scanpst.exe tool on the .pst files you find.
After repairing the .pst files, attempt to start Outlook 2007.
Let us know what happens.