Dell Inspiron 1545 Freezes After Several Minutes?

About a week ago, I was stricken with a BSOD, can't remember the error code. After that, the computer ran like crap. Even in Safe Mode, it ran like crap, constant freezing after about a minute after boot up. I did a little research and found that registry errors can be responsible for this, so I ran a couple different registry cleaners and it seemed to have done the trick. A couple days later, it went back to running like crap.I did a complete reinstall of Windows 7, and still runs like crap.Every time I boot up in normal mode, after about five minutes, the computer freezes up. The mouse pointer still moves, but is unresponsive to function changes. Meaning, the pointer doesn't change from arrow to hand to I-beam, etc., and clicking does nothing. I don't even get the "(Not Responding)" tag in the title bar of the software. Ctrl+Alt+Del does next to nothing. The best result I get from it is a blank, black screen, and I have to shut down manually by holding down the power button, which is the case 100% of the time, black screen or not.The computer runs perfectly fine in Safe Mode with Networking. I'm writing this post on it right now.Someone suggested I remove one RAM stick at a time and test the computer with one RAM stick in, changing it from one slot to the next, then testing the other stick. Did that. No results.