Repetitive alerts!!!! Malicious Url Blocked

see the image guys i m getting this alert again and again…

do suggest me ny solution to get rid of thiss

http://s1001.photobucket.com/albums/af132/passwaala/?action=view&current=aLeRt.jpg

Your system is very likely infected. Please try running a boot-time scan and report the results.

Thanks
Vlk