|Did you check your heatsink for dust? That could cause it. Maybe get a can of compressed air and blow out your computer anyway, you'd be surprised how much dust that removes (make sure there is no power coming into the system when you do this, however). |
If that doesn't do it, are you overclocking? If you are, you might want to stop and get a system that's designed for it - lots of gaming systems actually support overclocking because a lot of people in the past were doing it anyway.
Barring that you might in fact want to get a new motherboard for your system, but before shelling out cash there are a few things you want to ask yourself:
1. Do you know how to replace a motherboard yourself? If you don't, that will significantly affect your price for a new motherboard, since you'd have to pay someone to install it for you.
2. If you bought a PC from an OEM, is it still under warranty? Take advantage of it if it is, you could get the motherboard replaced at no cost to you, even if a tech has to do it for you. A computer is probably the 1 electronic device that's worth getting an extended warranty on, the last PC I had before the one I do now I had about 3 motherboards replaced on it which paid for the extra cost of the warranty about twice over.
3. If you've already replaced the hard drive, video card, and power source I'm guessing that's around $300-500 you've already spent on your computer. I can pretty much guarantee you that a new motherboard will start at $250 to replace - and that's if you do it yourself. You can likely double that if you need a tech to do it. At this point it might be cheaper to cut bait and walk away from your current PC and just buy a new one.
4. Keep in mind that a new motherboard - if it works - will likely only give you a certain amount of borrowed time on your current PC. The average lifespan of a computer is about 4-5 years, so expect your PC to remain working for 1-2 years more at most, anything after that is a bonus. Is it worth it to shell out potentially $500 on a new motherboard now and then spend minimum another $500 a couple of years from now on a new PC? That's something you'll have to answer for yourself.