Random BSOD codes, cannot get into Windows (even in safe mode)

Hello all. Let me describe the situation. I posted this on a different websites forum but it never went anywhere. I was wondering if you all would be so kind as to take a look.

"2 years ago I built my own PC, and every component was brand new, except my hard drive (which I got a new one shortly after). I installed Windows 7 and everything was going great during the install until my computer BSOD. I think to myself "Ok..." but the computer restarts successfully and I just shrug it off in the typical "Oh Windows... :P" fashion.

Jump to a few months later. I start having BSOD every few start ups, until it eventually got to where it was more often that not. The odd thing was, it would only BSOD during startup, and once it was up, it ran like a champ. So my lazy solution was just usually put my computer on standby. Well, then comes a day when I have to restart my computer for some program or driver installation, and the computer never comes back on. Try to use Startup Repair on the Recovery Disk, but to no avail. I suspected my RAM, so I swapped it out with another (compatible) set I had available. Unfortunately, the computer would never start up. It would literally not power up. So I ended up replacing the motherboard. Now my computer starts up fine, and my computer seems to be normal until...

The BSOD soon returns, and I suspect that it could be a software issue. I reinstall Windows. This seems to fix the problem... for a little while. A few short weeks later the problem returned. I am severely frustrated at this point. I can't get Windows to boot more than 1 out of 20 start ups. I start running diagnostics. CHKDSK, memtest86, Seagate's Hard drive tools. Eventually it gets to where Windows won't start at all. What's worse, the recovery disk won't even boot. If I'm correct, this means that it can't be a hard drive issue?

I had a copy of Ubuntu available, and I install that on a small partition I hadn't used yet. It boots some of the time. Other times, it has issues as well.
So my question is, if I've replaced the motherboard, run Memtest86 with no errors, and am unable to boot to the recovery CD, does that mean that it is my processor at fault? From what I researched, processor defects are rather uncommon, and usually due to over heating (and I have a pretty substantial cooling system). The other thing that's niggling my brain is that my computer can run sometimes. For instance, I'm typing this on Ubuntu right now. If the processor is messed up, how is it running this at the moment?"

I posted that about a week ago. Here's the updated status. I don't know what is wrong. I put my SATA drive (the original) in a different, working computer and it wouldn't start up either. So I switched to a different IDE hard drive and formatted it and installed Windows. It works for a few runs before it stops working completely and now no matter what I cannot get into Windows. Safe mode doesn't work. It crashes on the boot CD. Some (but not all) of my BSOD are actually green, but I don't know if that means anything special. Here are some of the stop codes I've been getting:

Code:

0000001E
0000003B
0000000F
000000F4
0000001B
00000050
000000FE

I also tried a different installation disk just to check that my current one isn't corrupted. Unfortunately due to the crashes I am unable to access any DMP files or minidumps or anything Any help is much appreciated.

P.S. This might be a dumb question, but I've never actually had to do it before. If I am unable (with your help ) to repair my computer successfully, where do I take it to be repaired by a professional? The only place I could think of is Geek Squad at Best Buy but after talking to one of their representatives it was very clear that I had a better chance of fixing it myself than they did (couldn't tell if they were ignorant or trying to sell me something. Probably both).

EDIT:
My system specs:

Code:

Motherboard: Asus P7P55D-E LX (BIOS version 2.61)
Processor: i5-750 Lynnfield 2.66 GHz LGA 1156 95W Quad-Core Model BX80605I5750
Heatsink: Cooler Master Hyper 212 RR-B10-212P-G1 120mm
Memory: G.Skill 4GB (2 x 2 gb) 240-pin DDR3 SDRAM 1600 (PC3 12800) Model F3-12800CL9D-4GBNQ
Graphics Card: Sapphire 100314-3L Radeon HD 6870 1 GB 256-bit GDDR5 PCI Express 2.1 x16
Power Supply: Corsair CMPSU-400CX 400W ATX12V V2.2 80
OS: Windows 7 Home Premium

Sorry if I was unclear, but I am currently using an old Seagate IDE drive. I pulled out my newer Western Digital SATA drive to see if it was just a hard drive issue. But I get the same results with either drive.

Now I am in front of a PC. Please update your system specs at the bottom left of your post.

Most importantly, exact make and model of your MoBo, and go into your BIOS and get it's version. Also, while in your BIOS, select the option "load failsafe defaults".

If you have tested the HDD on another computer and confirm it to be good then you need to do some Hardware Diagnostics.

First, if you are overclocking, stop
Second, follow this tutorial.

Post back results.

Were you able t get this resolved?