I had a SQL server 2008 (Express edition) installation in my Windows 7 (64 bit) and it was working fine. Couple of days back,i installed Microsoft Security Essentials and now when i try to open my SQL management studio,it didnt work.So i went to services and found that it is Disabled.I changed it to "Automatic" and and click on the "Start" button to start the service. I am getting the following error then

I checked the event log and found this.

Any thoughts how to get rid of this problem ? Thanks in advance.