A computer of mine randomly shut down (didnt just go to black - went through the standard windows shut down procedure) after using the alt + tab function several times to tab through a game and another few windows i had up, along with that I pushed the windows key a couple times also because the computer was being unresponsive for a few seconds. Shortly after, the computer gave some message which i cant remember and then went through the shut down process. I didn't think anything of it at the time so I didnt pay attention to the message. Anyway, after it shut down I cannot power it back on anymore. Pushing the power button does absolutely NOTHING... It has nothing to do with the power supply (I think) because when it's plugged in there is a green LED on the motherboard that lights up and when it's unplugged the LED goes out. I've looked for possibly burnt out cards in there and haven't noticed any (I havent looked very hard). I'm extremely confused about what happened here and if anyone out there has any possible solutions to this that would be great!

thanks in advance!

By nothing you mean you don’t even see anything on the monitor? Can you get into the system BIOS? Is the hard drive LED showing any activities? There could be a lot of reasons for this to happen, but from your description it seems as if the hard drive died on you. See if you can swab it in another machine to see if it works; or you can try another hard drive in your original machine.

nothing at all happened, fans didnt turn on or anything. i ended up finding out that even if the power supply is giving power to the motherboard, its possible that the computer wont turn on (i really dont understand that). but anyway i swapped the supply out with another one i had lying around and everything worked fine. never thought the power supply could have been the problem.

Actually the power supply can be a major problem; that’s how I lost my last machine. But I didn’t suspect it to be the culprit because you mentioned in your first post that it was most likely fine, and that it was the hard drive that was causing problems. Anyway, good thing that you got it sorted out and thanks for the feedback.