Computer restarts

[hatesbluescreen]

Whenever my brother-in-law trys to play a video off of youtube his computer will restart.
Is it something wrong with his motherboard or graphics card?

Thanks!

 

[Fragrant Coit]

It could be any number of things.... Do you have any specs about the PC?

1st off I'd rule out the RAM and Hatd Drive as possible culprits by running Memtest http://www.memtest86.com/ and the Hard Drive Diagnostic for whatever vrand of drive he has https://www.techspot.com/vb/topic7602.html .

Any failures, and you've found your problem.