PC shuts off while in game

.....When PC was first made and used. While gaming there were high voltage readings from Asus. they were too high and it was like that for perhaps a week or two. Turns out it was overclocked vis Asus so that was turned off.

Before it was turned off there was this issue "Graphics driver has stopped responding and has recovered" and now that CPU overdrive was turned off, that issue still persists and won't stop happening. There were less intensive games that did not affect this.

So for months this issue continued and at some point, there were graphical glitches in games where this error would happen and this glitches happened often. At some point, the glitches would become too intrusive and huge until game is restarted.

Tried turning off the default AMD overdrive and that did not help, also tried installing many drivers over and over to find the right one. Even installed multiple operating systems on all hard drives(the AMD cleaner caused issues on other OS and now only one is left where UAC works).

So now on a brand new Windows 8.1 Enterprise and still this continues although it happens less often due to tdrdelay(maybe, I do not know). No graphics driver stops this. UAC stopped functioning on the other OS, setting CPU to power save doe nothing. Setting power settings to power save decrease performance. then blue screen happens when PC is on for days.

And now, the PC started shutting down while gaming. I admit trying the AMD CPU Overdrive a few times over the months on several different OS on the other hard drives. Soon after the final attempt, the PC started shutting down while gaming(Only intensive ones).

So to stop it, I lowered power in overdrive to -20%. lowered clock to 755, than 700, then 655 and now 605. And memory to 1155, then 1055 and then 1005 as a trial and error thing. it was fine at 755/1155.

Decided to see if GPU only needed to be this way to put CPU on turbo and it shut down again, tried standard, shut down, power save now and shut down. Also, the fan is at 100%. Lowered clock and memory and still shutdown while gaming. kept doing it as it continued until 605 clock/955 memory..

Now the shutdown usually happens after PC has been on for a while and chrome is open. Well, i do have a lot of chrome tabs open and 3 windows. uess I have to trim that now. Funny thing is, it does not happen when PC is first started. usually waits until later when chrome is open.

Tried searching fr the issue but nothing came up. So gave up and decided to post here.

So what could be causing this? And what may help stop it?

Note: When it shuts off, have to turn power switch off for 5 seconds to turn PC back on. Also, I use to keep PC on for days until the shut down happened. Only restarted it every now n then and rarely gave it a break. Also, it also shuts off while in sleep mode.

Note 2: The BSOD error message is "irql less or equal". And the PC is currently open and has not been dusted at all. the fan is starting making a weird noise then stopped with that noise after blowing it. Currently don't have any cleaning duster.

Also, would a box fan with 3 speeds help at all if next to PC?