My computer has been running just fine for almost 4 years. Then in mid-September I started having problems and getting BSODs. Nothing really changed hardware-wise, except for adding a 512 stick of RAM on August 26. I didn't figure that was the problem, because there were no problems initially. I've gotten the following bug codes: 0x0000008E, 0x00000024, 0x00000050, 0x0000007E, 0x0000007F, 0x000000D1, 0x000000A. And these messages: DRIVER_IRQL_NOT_LESS_OR_EQUAL, IRQL_NOT_LESS_OR_EQUAL, PAGE_FAULT_IN_NON_PAGED_AREA. All these drivers have been mentioned: kmixer.sys, nv4_mini.sys, win32k.sys, rdbss.sys, sr.sys, ntfs.sys, and others. Some drivers mentioned were from Norton Anti-Virus. So I uninstalled it completely and the errors referencing those files obviously stopped. But other BSODs persisted. I tried cleaning out the dust in my case, running lots of spyware and anti-virus programs (in safe mode too, however I got BSOD in safe mode!), updating all my video/audio/other drivers, updating BIOS, and testing the RAM. I got one error on Test 8 and Test 5 using memtest86+, with 2 identical Kingston 512MB DDR PC2100 ram sticks inside. Then I decided to switch out my new RAM stick, thinking it might be the problem because it was the most recent change to my computer. However when I took it out, the problems continued. So then I moved my other existing RAM stick to a different DIMM slot. Problems continued. So at this point I figured it wasn't RAM. So I put my new RAM stick back in with the my existing one. When I switched on the computer a REALLY, REALLY BAD SMELL come from the case. So I immediately shut everything off and opened up the case. The new RAM stick had been scorched slightly, there was a small burn mark on it and black smudges on the gold contacts. I pulled it out and the contacts on the DIMM slot also had black smudges on them, so it might be damaged. The power supply also smelled, I thought. So I removed it and opened it up, nothing looked burned. I tested it on a different computer, it worked. Plugged the PS back into my computer, and switched it on with my one existing RAM stick in there. No bad smell, everything worked correctly. However the BSODs continued! This weekend I decided I would reformat my hard drive and do a fresh install of Windows. As Windows was installing I got a BSOD, so obviously Windows wasn't the problem. Eventually I got Windows fully installed and all my stuff restored. And the BSOD continued. I tried testing my one existing RAM stick with memtest68+ and Windows Memory Diagnostic. In WMD, I got one error in the LRAND test on 6 passes out of 10. In memtest68+ I got one error on Test #8 in 5 passes out of 5. This RAM stick worked fine for 4 years. Could it, out of the blue, start causing problems? And what about the other RAM stick "exploding"? Could the motherboard have gone faulty? Hard drive, video card, PSU? What is it? I just can't figure this out. It's weird that everything ran fine for so long and now just stopped working. I've attached my 5 latest minidumps.