Any comments on this shaggy dog story that is over .. for a while I hope! HARDWARE BASICS WinXP Pro with SP2 and all updates Asus A8V Deluxe Motherboard, 2GB RAM WDC SATA 200GB drives mirrored (Promise controller) at time of crash now split with only one drive in place Drives have 2 partitions, one for documents, etc, the other for the O/S, programs, etc. BACKGROUND After many months of good operation, and no immediately preceding installs, other than possibly auto updates of McAfee virus scan and WinXP, the System started from a cold boot to absolutely consistently going to BSOD with "Bad_Pool_Caller" after Window's loading of a bunch of drivers, the last being gagp30kxk.sys. The error code is 0x00000007 (0x00000CD4, 0x02090026, another) where "another" varies a bit. OBSERVATIONS Safe mode is NOT accessible. To try to isolate the problem the following were removed/swapped out for known good: memory, video card, CD drives, ethernet NIC, and the hard drives removed one at a time. The system ran fine under DOS and a PEbuilder CD with the O/S on it, both of which just provide a command prompt. Chkdsk and WDC diagnostics were run from DOS on the HD drive. The (now single) drive can be accessed with WinXP setup disk and raid drivers on a floppy going into Repair mode. Infection by a virus/worm/etc. is unlikely as the system is protected by a router, software firewall, antivirus and antispam software, and my good nose for bad eMail. QUESTION I want to avoid wipping out the partition and reinstalling considerable software, so I am looking for a way to reinvigorate/reinstall WinXP that will hopefully retain the software environment ... at least long enough to uninstall selected troublemaker candidates. HELP! ANSWER A WinXP repair job fixed it. The nVidia graphics driver had to be reinstalled to regain functionality, and two miscellaneous files needed to be restored, but the latter were probably irrelevant to the failure. The mirrored pair are not together yet, but that will have to wait. We booted from the WinXP CD with Raid driver diskette in hand and selected install rather than repair console, and then it offered a sub-menu which included repair of o/s as distinct from full replacement install. From there it was a straight forward exercise. Nowhere had I seen that option clearly mentioned. CONCLUSIONS While we can only guess in retrospect, but the most likely failure point was a "hosed" graphics driver. This would tie in with the last driver to load during the failure period being a Via chipset specific driver that interfaces between the chipset and the AGP port. Although almost all of the messages I found on the internet blamed the Bad_Pool_Caller message on a hardware failure, and by far most often on memory failure, it is clear that those explanations just missed the mark.