Blue Screen Errors

Sometimes fixing similar Blue Screen of Death(BSoD) error messages isnt as easy as it seems.

When you have an IRQ_NOT_LESS_OR_EQUAL error, the first thing you do is swap out the RAM; but when you add DRIVER_IRQL to the error message, it becomes much harder.
You might think, as I did, swap out the RAM first. That doesnt work. You might also think that there is a driver issue, after all, the error message says 'driver' in it.
Ok, but which driver? In my case, it was a video problem. Changing the video driver didnt help.

Now, you might be thinking, Google for the answer. I did; at least 4 different answers, including Microsoft's. All of them suggested something besides the RAM and the video drivers; so I tried them all (Microsoft's answer was to change the video drivers).

After everything was tried, I used System Restore and went back further than the time the problem had occurred. I got the rid of the video problem, but the Blue Screen remained.

If you know a definitive answer, I'd love to hear it.