I have a Windows XP Home 32-bit system, Upgrade SP2 CD install from Win98SE, then upgraded to XP SP3, and all other critical updates installed. The motherboard is an ASUS A7V400-MX, and I have installed all the latest drivers for motherboard hardware and the AGP video card (ATI Radeon 9700 Pro). There's also an Intel 537ep-based PCI modem. The driver/software CD for the modem says BVRP and Xmedia on it but I don't know if either of those companies is the actual maker of the modem; Intel supposedly only made chipsets and not complete modems. Whenever I try to make any changes to the parallel port in the BIOS, the system crashes to a BSOD at startup, with the following info: PAGE_FAULT_IN_NONPAGED_AREA (...blah blah blah...) STOP: 0x00000050 (0xFFFFFFE8, 0x00000001, 0x804D9044, 0x00000000) This even happens if I merely uninstall the parallel port in Device Manager, without making any BIOS changes. Happens if I uninstall in Device Manager, and set to "Disabled" in the BIOS... in short, no matter what BIOS settings I try for the port, whether I uninstall the port in Device Manager first or not, I can only get the system to boot again if I return the BIOS setting for the port to its present configuration (ECP mode) then hit F8 during boot to "Load last known good configuration". I have done some searching online and found that most info on 0x50 Stop Errors says it's probably bad RAM, but MemTest86+ finds no problems with my RAM. I am using MS Windows Security Essentials for virus protection and firewall. Please let me know if there's any other important info I forgot to mention. TIA for any help you can provide.