Hello all, Stumbled upon this very useful forum while googling for information on BSODs. I've browsed some of the topics and unfortunately, find that my PC suffers from a multitude of them - the reboot loop, repeated BSODs, etc. I've done the necessary diagnostics using memtest and orthos and indeed, with my current mobo (ASUS P5VDC-X), pretty much all the RAM modules I have fail the tests with errors writing to ## or inaccurate division (the 0.5/0.4 message that orthos spits out). However, on a different mobo, these very same RAM modules pass an overnight memtest and orthos run. This gets me puzzled - is it a RAM problem or my motherboard? I am currently using no-brand Nanya PC2-4300 512MB X 2 mem modules running at 310MHz (on a Pentium D-805 at 3.10 GHz.) Despite the errors from memtest, it seems stable for normal tasks until I start a game...then the game will quit abruptly with an error. I reverted back to stock settings and the same things occur. At this point, I can start XP only with these mem modules. (I removed Vista since the boot manager was really getting screwed up and when I boot from DVD, after the loading process, I keep getting error messages.) When I switched to my newly bought Kingston ValueRAM DDR2-667 1GB X 2 initially, I kept getting random restarts all the time. Now, my machine goes into a repeated reboot loop or if it manages to get past that, says something about corrupted BIOS (even after I cleared the RTC RAM and reflashed it) ) _and_if I manage to get past that, it's BSOD galore. (at stock settings) I try to boot from CD but once the drivers finish loading, I get a BSOD when the message "Windows is now starting" comes up...I can't even get to press R for repair! I'd appreciate any insight! I thought DDR2 RAM was backwards compatible and I could possibly achieve higher overclocks but at this point, I may have wasted my money. Also, since the same RAM modules work with no errors in another machine, is it still a RAM problem? I'm using a 430W PSU with an AGP 7600GT that requires an external power connector, a SATA HDD and an IDE DVD-RW. Thanks in advance for any suggestions!