BSOD won't end!! Tried everything....

Hey guys, I am desperate for some BSOD assistance, I've tried just about everything on my own already and nothing seems to solve the issue. I get different BSOD errors, sometimes it's the page fault, or IRQL not less or equal, or the bad pool header....I've ran Memtest, found some errors with my ram or ram slots, so I removed half of them which left me with just 3gb. I ran all kinds of registry cleaner software, scanned and fixed. I updated my BIOS, changed to Windows basic, reinstalled my video card driver, ran windows 7 startup repair, scanned for viruses, etc. to no avail. I still don't know whether it's a software or hardware issue, but I have run out of ideas on what to do next. If someone could please assist me I'd really appreciate it. I could just reformat at this point but I have so much important software installed, and I don't want to have to reinstall everything, it will drive me insane to have to do that. I hope someone can help me. Thanks.