If Microsoft Outlook does not open, restart the computer just to ensure Outlook has been closed properly the last time it was used and to clear any stuck processes. If it still does not open after this, press the Windows key and R to open a Run window. In the dialog box, type outlook.exe /safe then choose OK to open Outlook in Safe Mode. Opening Outlook in Safe Mode should eliminate whatever problem is causing it not to load, and allow it to correctly load in normal mode the next time. If this still does not fix the problem, try a repair on Outlook. To repair Outlook, open Programs and Features on the computer and locate Microsoft Office (or Microsoft Outlook if you are using the standalone version) in this list. Select it and then select Change. Select Online Repair from this screen to see if it will correct the issues with Outlook. This will take typically 15 minutes or more to complete.