Graphics help

[patsfan258]

First of all start off saying this is my first post (long time lurker) so pardon me if I managed to post in the wrong forum.
I recently built my own desktop about 2 weeks ago and now I have run into some problems.
Every time I play games my computer will freeze up completely and some times stay frozen like it did last night. And every now and then on a rare occasion it will even lag on simple youtube videos.

I was wondering this was a faulty graphics card or maybe something else was interfering with it? Not really sure.
Possible intel HD drivers interfering? If so how can i fix that?
My set up is: i5 3570k, 16gb of ballistic crucial ram, ASRock Z77 Extreme4 motherboard, and a GT Geforce 640.
Thanks in advance for any help!

 

[patsfan258]

Well I made some progress I suppose, now when my screen goes black after a crash I get the Nvidia has stopped working and has recovered. Still haven't found a fix though, any help would be appreciated.

 

[vinaykumar5320]

Seems like a problem with the PSU. What PSU are you using?

 

[bystander]

The crash that says your drivers have stopped working and recovered can be a result of overheating as well as lack of power. You may want to run a hardware monitor to see if the card is overheating.

 

[patsfan258]

My PSU is OCZ ModXStream 780W. I have an Nvidia desktop widget that shows that the cards temperature is about 40 degrees Celsius right after it crashes.

 

[patsfan258]

Okay so I am still experiencing this problem. Whenever the graphics card is under 40 degrees Celsius it seems to work perfectly fine but over 40 is when i experience my lag. Still haven't found a solution. (I am playing LoL if that matters at all.)