i recently did a major upgrade, replacing almost every component in my system. i experienced an occasional bsod, but not enough to worry me, so i ignored them...until now. for the past couple of weeks, i've experienced a lot of bsod and hope someone here can point me in the right direction to get this resolved. i've noticed that since upgrading to sp2, i've gotten them a lot more, but i'm not ready to blame sp2 because before i installed it, i was getting them. i've updated all my drivers, taken out 1 stick of ram and fully tested the other one (only have that 1 stick in my sys now) with memtest for about 12 hours - 7620 cycles, 18,479% coverage, with no errors. but, when i put that first stick back in - bam - instant pfn_list_corrupt message on a bsod. for now, that bad stick is not in my system. i have a suspicion it may be the hdd (see below), but at this point, i really don't know. i have updated my sata drivers to the latest, but i think xp pro has issues with sata drives since the technology is fairly new. i'm not even sure where to begin after testing the ram. any help would be greatly appreciated. and yes, i've looked all of these up via google, but microsoft is super-vague about where to start. they say to check all drivers and software updates. and the forums i've looked through are also vague and offer no real solutions. here are the bsod i've been getting (doesn't matter what app/game/etc. i'm using): 1. bad_pool_caller stop error 2. page_fault_in_non_paged_area - filename on the bsod is: partmgr.sys 3. pfn_list_corrupt 4. irql_not_less_or_equal stop: 0x0000000a (0x00000001c, 0x00000002, 0x00000001, 0x8053bee9) - i get this one a lot! 5. after rebooting from error #4 above, i got a "generic host process for win32 services" general windows error, with the "send" "don't send" screen. that's the svchost.exe file it failed on. ok, here's my current setup: yes, i know the overclocking may've caused these, but i have kept an eye on my temps and everything is fine. i've even dropped my 1 stick of ram back down to default settings in the bios. asus a7n8x e-deluxe mobo amd mobile barton 2500+ (1.83ghz) @ 2520mhz thermaltake volcano 12 hsf 2 x 512mb geil ddr400 pc3200 @ 2.5 3-3-11 (now 1 512mb stick at default) wd 74gb raptor 10,000rpm sata snd blaster 5.1 gamer gf fx 6800 gt 256mb (default settings) hp 9500 series cdrw sony dvd rw dru-530a enermax 430w ps marvell yukon gigabit ethernet (onboard) 10/100/1000 nic win xp pro sp2 i've run complete virus (even with show hidden files enabled), spybot and ad aware scans and she's squeaky clean. i think that covers just about everything. let me know if additional info is needed. again, any help is appreciated.