Cannot Start outlook 2007

I have vist and windows 7 installed. i am able to dual boot and have been using Windows 7 almost exclusively.
suddenly, today, when i try to open Microsoft Outlook, it starts opening and is almost rendered when i get the following error message
“Could not start Microsoft office outlook.Cannot open outlook window. I can not understand how and why this happened out of the blue. I am using AVAST antivirus as i have been for a few weeks now. Nothing else has changed. Reinstall of office made no difference. Outlook still runs perfectly on my laptop and i am also running Windows 7 and the same antivirus.
Can anyone help?