This morning my computer had rebooted due to an automatic windows update. When I tried to open Microsoft Outlook 2007 I got the following error message:

"Cannot start Microsoft Outlook. Cannot open the Outlook window."

This is the second time that it's happened to me so rather than google for 10 minutes to find it again, here is the solution that worked for me. Go to Start -> Run and enter:

Outlook.exe /resetnavpane

And it will be fixed. Yay!