As David has rightly pointed out the reloading of Windows means the software is not the issue, it is hardware related. You need to look at the BSOD Stop code to see if it points at a particular hardware item, often they are a bit generic and it is difficult to tell.
But you may need a bit of trial and error to find the cause, and as you have suffered from a power interuption it could actually be more than one thing anyway.
The first thing to do is remove all the cards and modules attached to your mainboard, and simply reseat them, it may be just a coincidence and this will resolve any "loose" items on the board.
Scan and test the hard drive (all of them if more than one) and the RAM.
IF you have more than one RAM module scan them all to start with, if it fails then scan individual modules to try and find the faulty one, if none come up as faulty when individually scanned then the chance are it is perhaps the board slot that is the fault, put a module back into a different slot and re-test to see if you can determine if it is a dodgy RAM slot.
If you can, test the VGA card as well, these can sometimes take a bit of a pasting when the power kicks back in.
But chances are your first theory is correct, it is the PSU, they are fairly cheap to buy and if it turns out to be not the fault then you can either keep it as a spare or just replace it anyway and keep the old one as a spare.