I have seen this topic posted many times in several forums, but in reviewing the messages and responses, none seem to apply or resolve my situation. I am posting this in hopes of some fresh help. I have a Dell Latitude D800 laptop (2003 era) with 250GB (IDE) drive (replaced about 6 months ago) running Win XP-Pro, SP-3. One day I shut it down, then the next day it wouldn’t boot up. No new hardware or software installed for ages (perhaps other than Win & McAfee updates). The POST screen displays momentarily, but then it goes black with an unmovable blinking cursor in the upper left hand corner. I’ve disconnected and unplugged all cables and peripherals to no avail. Attempts to boot into safe mode with F8 key are fruitless, as is Cntrl-Alt-Del key. I can boot from CD via F12, enter BIOS set-up via F2, or run Dell diagnostics. I’ve booted from into Windows Recovery mode via the OP Disk CD and done repair, and also invoked “bootcfg/rebuild” command, all to no avail – black screen/cursor still returns. I can see no obvious command in the BIOS that if changed might solve the problem. One odd thing however, is that the hard disk capacity in the BIOS reads 137GB, yet the capacity is 250GB. If I had to guess, it would almost seem like this is closer to what might’ve been available free space on the disk, as though the BIOS can’t see a large portion of the disk (yet when booting into recovery mode the operating system appears to be recognized on the C drive !?). I cannot figure how to troubleshoot this, however. I’m obviously trying to preserve and save my programs and data already on the disk. I ran extensive diagnostic tests, and all hardware passed all tests, including the hard drive tests. One exception was an error message indicating a failure of the “NIC EEProm Test”, device Broadcom 5705M, Error code “3B00:0781” – all greek to me, but seems to indicate a hardware failure in the networking circuit, seemingly built into the motherboard. So I spring for a new motherboard and replace it, but when I boot up it indicates “Invalid Configuration information” & “Time-of-day not set”, and wants to run a set-up utility (also no Dell service tag number – not sure if that has any bearing). The “press F1 to continue” route yields nothing, but the “press F2 to run set-up utility takes me back into the BIOS screens. I reset the clock with the proper time, then re-boot – arrrggh !! - black screen with cursor again. Same behaviors and actions as before. I reboot into Dell diagnostics again and run extensive tests again, this time no errors, not even the NIC EEProm test error (limited success ?). I’m thinking maybe the CMOS/NVRAM data might be corrupt. I check the CMOS battery (weird Dell configuration, but 8 yrs. old now), it’s rated at 7.2V and checks out at 8.1V – seems okay. Perhaps erroneous or corrupt information is acquired from the hard disk during boot-up and transferred into the CMOS data corrupting its addresses and stalling the boot-up. I’m lost – unclear how to proceed from here. Have I been attacked by a virus ? How do I troubleshoot and resolve this ? In checking some forums the problem seems somewhat common, but others seem to have resolved it from Vista or Win-7 operating systems which probably have more robust recovery options. Again, trying to save my data if at all possible. Can anyone help ?