It appears to be a problem with the driver for the Dlink wireless card, and a conflict with this Win 98 PC now running XP. There were enough incidents of blue screen death, but the last time I reformated I did not install the driver. This has been very inconvenient as this big HD in that PC was for backups of my other 2.
However it's now overdue for the boot to fail, and there have been no blue screen lockups.
ATF