Windows 7 Computer is Randomly Restarting

[tlt593]

My computer is randomly restarting and I'm not sure what the problem is. It has happened throughout the year but it stopped for a really long time, about 7 months, and now it is starting to do it again.

Here are my specs.
Gigabyte GA-790-FXTA-UD5 Motherboard
AMD Phenom II X4 965 Processor (3.4 GHz)
MSi Frozr GTX 260 Video Card
6GB DDR3 Ripjaw RAM
650W Cooler Master PSU
1 TB Samsung HDD

Any help would be appreciated, I think I might just take it to a computer repair place to see what the problem is.

 

[Saltgrass]

You may have gotten a device driver update through Windows Update, so check for that.

Have you changed anything on your system?

Have you moved it or have it plugged into a different place, or a UPS?

Have you been getting any warning or error messages in the Event Viewer?

No Overclocking?