[Phillips1990]

My computer has been randomly restarting itself so I guessed it was a virus. It wasn't. Scanned my computer no viruses. I went into BIOS and checked the temperature and it said 88C. So I'm guessing thats the problem? It's showing 2 fans but one is at 0RPM and one is 4000+ RPM. Any tips?
-Update-
Installed SmartFan. Ran it. These are my temps.

[Jngoi]

I encountered the same problem. I am in the Philippines so it is hot and humid. I tried to look for solutions but drawed reponses like it's a 2 year old device which is regularly used so it's just normal that the processor tends to get hotter easily and then causes the unit to simply shut down while being used. I resorted to cleaning the unit myself to make sure it's as clean as possible, opened the side covers, arranged the wirings to ensure that the CPU, chips, graphic cards, etc. gets plenty of ventilation and placed a small but high powered electric fan on it. It has to date, not shutdown by itself.

[Phillips1990]

Could it be because it is hot weather today? its 85F right now. Suppose to be 90F tomorrow. I do have a fan on it with the side cover off. Hasn't been restarting for a bit.

[Rich-M]

That is way too hot for cpu and the fan is working really too hard also.
I would bet you need to reseat and clean cpu and hsf grease off and replace it or the hsf needs replacing.

[Jngoi]

I had, just out of curiosity removed the fan and the heat sink on top of the processor ( be sure to be wary of how the latches are removed ) and had discovered that the fan and the heat sink to be covered in dust and grit. I washed the heat sink over with tap water and left in out to dry and vacummed and cleaned the fan out. I will put it back tomorrow and see if that help s.The fan installed over the heat sink is designed to suck the hot air out from underneath, not to blow air into the processor, the dust, grit and grime blocks the passage of air. I also remembered, graphic card manufacturers opted to put in heat sinks in their products in lieu of fans because fans short themselves up after sometime. Maybe the fans shorted out or something.
Also the best layout is for a fan to be in the front part of the casing ( there is a slot for air to be pass ) sucking air into the computer, passing the hard disk and cooling it, passing the motherboard, CPU and the cards ( make sure your wires are kept to the sides or between the optical drive to ensure that air freely circulates inside) and then sucked outside another fan mounted at the back of the casing about below the fan that also sucks the hot air out of the power supply. if that doesn't do it, open side casings and electric fan will do the trick.