I've been having a similar problem, I can run for 2-3 days straight with no BSOD's then I may get 2 in one evening. The annoying thing is that the error message is different almost every time...
IRQL_LESS_OR_EQUAL
BAD_POOL_CALLER
PAGE_FAULT_IN_NONPAGED_AREA
And one about filemgmt or filesys (can't remember didn't write this one down)
I did some inital troubleshooting, memory diagnostics, MHDD scan, CHKDSK, CCleaner for registry and temp files etc...
I'm 99% sure that none of my hardware is defective (having never had a single BSOD with this hardware on my previous 3 installs of XP). Therefore i'm led to believe that it's a driver/software related issue.
Does anyone have any particular advice in to tracking down which driver could possibly be responsible... I really want to avoid flashing anything, particularaly my BIOS. I tried using a program called RadarSync to check my driver versions, this reported that some of my drivers, mainly my mobo chipset drivers were out of date... I thought this strange as this is a fresh install of Win7 64bit so the drivers I'm using were all downloaded about a fortnight ago.
Here is my rig spec:
Intel Core 2 Quad Q6600 G0 Stepping (2.4GHz 1066MHz) Socket 775 L2 8MB Cache @3.2GHz
ASUS P5K-E/WIFI-AP AiLifestyle Series P35 Socket 775 Socket eSATA 8 channel Audio ATX Motherboard
2 x Corsair 2GB (2x1GB) DDR2 800MHz/PC2-6400 XMS2 Memory Non-ECC Unbuffered CL4
Creative X-Fi Xtreme Gamer Soundcard - Retail Boxed
PowerColor HD 4870 1GB GDDR5 Dual DVI HDTV Out PCI-E Graphics Card
NEC Optiarc AD-7170S-0S 18x DVD±RW/DL/RAM Serial ATA