Power Supply Voltage Readings

My computer has been acting up for some time now. I got the blue screen about three times. The first time I just decided to upgrade from Vista to Windows 7 and the other two times I just re-installed Windows 7 thinking it might have been some sort of virus + I ran chkdsk, windows memory diagnostic, and removed the dust from inside. After maybe a month I'm now getting random restarts and error messages saying computer had an unexpected shutdown. I'm thinking it has to do with my power supply so I got a multimeter to test the voltages while running Prime95. I get 3.3v= 3.35v, 5v= 5.06v, and 12v=11.65v sometimes 11.62v. I decided to also test it by just jump starting the power supply. There I get 3.3v= 3.35v, 5v= 5.02v, 12v= 11.88v. Is this a power supply problem?

The computer is completely clean with windows 7, all that has been installed is the Prime95 and google chrome and the restarts come randomly. The computer could have been used for an hour or a couple minutes, and all its being used for is browsing the web.

Thanks for the help.

ATX spec for PSUs is 5% on 3.3V and 5V, 10% on 12V. This is idle and under load, so on both cases, you're fine. Remember that there is also very small ripple on the line voltage (millivolts), and you need an oscilloscope in order to measure that.

http://en.m.wikipedia.org/wiki/ATX#section_3

That's what I thought. But it was the only explanation I could think of for what is happening to my computer. I have a 300w power supply, was gonna get anothet one but now I'm not sure what could be the cause for the restarts or shutdowns.