Why doesn't scanpst.exe help? What happens when you try?
Did it ever work after the upgrade?
Did it ever work before the upgrade?
Which method of transferring your pst-file did you use?
You can always restore from backup of course;
See
http://www.howto-outlook.com/howto/backupandrestore.htm
If this is your last copy and you need to keep the data within the pst-file
and the pst-file is beyond repair for scanpst.exe, then you'll need to use a
commercial recovery tool. Mind you; these do not come cheap.
I've had good results with Datanumen's Advanced Outlook Repair
http://addins.howto-outlook.com/datanumen_outlookrepair
If you decide to order use DNC-PUXB-HT to get a discount.