Why do my browsers tend to turn off when entering certain sites or performing some tasks on websites

The topic says it all - IE, Firefox and Opera. All of them tend to shut down for no apparent reason, for example on

http://www.systemrequirementslab.com/bon...

Whenever I choose a game to check and click on the "Can you run it?" button, the browser will simply turn off without any warnings. I tried scanning with antivirus software, but made no progress as nothing has been found with 3 different scaners. Anybody knows what might be causing my problem with them browsers?

Why do my browsers tend to turn off when entering certain sites or performing some tasks on websites?anti virus

busy server, i couldnt view a thing other than :

Server Busy! Please "refresh" your browser to try again

System Requirements Lab servers have alot of traffic at the moment.

We apologize for any inconvenience.

Cannot determine referrer

it's not your computer at all