Outlook Express Error: I can’t open my Outlook

I am using Microsoft Outlook to store my emails at work. It is very efficient and useful. But this afternoon, I encountered an error and I cannot open it again. I tried to restart my browser, and computer but nothing happened. I still can’t open my MS Outlook. I do not know what caused the error. I am using MS Outlook 2010. What can I do to prevent the error?
Microsoft Office Outlook
Cannot start Microsoft Office Outlook. Cannot open the Outlook window.
OK
