Windows 7 shuts down randomly?

I think It might be your PC might be overheating. I had an older PC that was shutting down and restarting at total random times. I replaced my power supply and it did not fix the problem it turned out the thermal paste on my heat sink was dried out and causing my CPU to over heat after use. I had to clean off the old paste and put some new paste on it and that fixed the problem of the random shut downs. I just wish I did not replace the PSU first and thought about it being a heat issue first

That problem can be caused by many things. Go to start and type event viewer, and check for critical errors. They should show the time of the restarts, and probably kernel power error, with the code 41.

Check out my thread, I just bought a brand new dell pc with windows 7 and had the same issue. The problem was the bios, I updated it and it works fine now.

New windows 7 dell pc restarts, no error or bsod

just to throw another stick in the mix, upgraded my system about 3 months ago Gigabyte H55MS2H mobo with i3 540 random shutdowns started straight away and i assumed the motherboard, when i spoke to the supplier they suggested it was the psu which was a 600w thermaltake from my old system and had served me well. so i swaped out the power supply with a new 550 thermaltake from another system. the 550 in my system worked fine and solved the problem, the odd thing was that the 600 in the other system also worked fine. interesting? well as i couldnt keep the 550, the 600 went back in and th problem continued, until one day it stoped, iv racked my brain trying to retrace what i could have dont, the only things that stand out are updating the motherboard drivers, replacing the backround picture and updating the bluetooth drivers. now the painful thing is i have done a clean install because i wasnt happy with the amount of crap on there and now my darling problem is back, i have upgraded the drivers and still no fix. i really pains me because i now know that it is a software problem i just dont know how to fix it.

Interesting... I am on this thread because my PC started doing the same thing! I followed the above instructions, and I have the right box checked as well. I installed W7 ... oh ... maybe a couple months ago and this just started. What a pain in my butcus.

Hello eujaynia and welcome to Seven Forums.

Couple more things you could try to pinpoint the problem.

Try the Performance Troubleshooter:

The next time Windows 7 turns off by itself restart in Safe Mode.
1. At Safe Mode desktop (weird screen with the words safe mode in each corner)click Start > Control Panel > Troubleshooting.
2. Double click on Troubleshooting to open the applet.
3. Under System and Security click on Check for Performance issues.

You could also install a free program like Speccy to get real time temperature readings to see if you have an overheating issue.

Speccy - System Information - Free Download