Try to open Outlook in safe mode and check.
Click Start->All programs-> Accessories-> run-> type ‘outlook /safe’ without quotes and click on ok.
If it works fine in safe mode, then disable add-ins in Outlook 2010.
Open Outlook-> Go to file-> Click on options-> select add-ins towards the left hand side-> Click on go for COM Add-ins-> Uncheck all the Add-ins.
Try to reopen Outlook 2010 and check how it works.
Ganesh Kumar N