windows 7 won't start even with install disk

When I turned on my computer it locked up in the starting screen so I tried boot repair and it locked up on loading files. I tried going into safe mode but it again locks up on loading files. I tried using the windows defender offline cd but it locks up on the windows logo. I tried creating another cd and same thing.

I tried putting the windows 7 oem install disk (home) and boot to it for the repair options but it locks up on the same starting screen like it does when trying to boot from the hdd.

For my job I HAVE to have this computer up and working before 7pm tomorrow! I'm freaking out. Help please???

btw, I tried disconnecting all the hard drives and it still locks up on the start screen. So the issue must be with the motherboard or power supply I guess?

I thought it was a RAM problem so I took one ram thing out and no change. So I swapped them seeing if maybe the other was bad, but then the powersupply turned on for a second and went off. I put both RAM in and it still won't even turn on now. I thought I may have shorted it but I looked everwhere (so did my dad) and we can't find anything. Everything is plugged in and now the PSU won't even recharge.

I was afraid maybe I shocked the motherboard or something, but even after unplugging the psu from the motherboard it still wouldn't reset. So I'm assuming the issue isn't the motherboard. And the PSU was working before I took the RAM chip out so it seems unlikely that it's the PSU.

What could it be???