Cannot start Microsoft Outlook. Unable to open the Outlook window

When trying to launch outlook you get the following:

"Cannot start Microsoft Outlook. Unable to open the Outlook window. The set folders could not be opened. The server is not available. Contact your administrator if this condition persists"

I have found the following to work for me:

Go to Run and enter "Outlook.exe" /resetnavpane
click OK

go to run and enter "Regedit"
click OK

1. Locate HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows Messaging Subsystem
2. Delete the Profiles key under the Windows Messaging (Subsystem) key.
3. And of course you need to reboot your PC to apply any changes in regedit. 

It is recommended to backup regedit.