Whenever, I attempt to play a online game such as minecraft or runescape my computer crashes and comes up with the blue screen. This happens every time about 5 minutes into the game even though all other windows are closed. Also occurs when the computer is in safe mode. I am not sure what the problem is, maybe the temperature or a virus. PLEASE HELP!

Run the following diagnostic for 'runescape':
Can You Run It


Did you try to run those games in an alternate browser? Which browser(s) wasn't working (IE9 and FF4 may currently HAVE INCOMPATIBILITIES for such games?


It would also be a good idea to update, where necessary, all your identified plugins in each browser on your system:
Firefox Web Browser

You can check for the compatibility of your game with your Operating if you find that you have no issues, you can also check the system requirements for running you games, if you need additional RAM you may need to upgrade it. If you find that your system has enough RAM, you may have some malwares running which are consuming a lot of your memory, in that case you can update your antivirus program fix all the malware threats in your computer.

For more info, click here

What do you mean by "crashes"? Does it get a blue screen with error information on it or does it just restart? If BSOD (Blue Screen Of Death) then run WhoCrashed and see what it tells you about the failures.