Outlook 2010 has crashed.
It has something to do with enabling / disabling Mobile Services add-on. I ignored it when starting Outlook 2010 for the first time. BAD IDEA!
It failed to open. I tried to open my Outlook 2007 instead. It failed to open too.
After trying a few different options including repairing of Office 2010 beta and trying to opening Outlook 2007 in safe mode, I ended up restoring my system.
So much for trusting a beta software. I should try this whole exercise on a Virtual PC or on VMWare image. Also, next time I am going to make a clean install.
After all these years, Microsoft has not perfected the art of upgrading a software.