Help. The computer had been a PIII 600 with Win 2K pro for several years, then last december I installed a new motherboard with Athlon XP 2200+ and huge CPU fan and a better video card (nVidea MX400 64mb). It was fine till this weekend when It failed to boot up to a dos prompt or Win 2K - just a black screen. It had the normal single startup beep, but it never even got to loading a BIOS. I pulled the HD drives and tested them in a USB 2.0 box on my laptop and they were fine. I then swapped the motherboard back to the original PIII 600 and it would boot up into DOS, and let me do the BIOS setup, and would even respond to the F8 to let me choose safemode or normal bootup. However, when booting from the hard drive, I find I am stuck at the "Starting Windows" and the white dotted line is fully filled in from left to right but it never goes to the desktop. I can boot up into Win Setup from a win 2K pro CDROM, and I have run the repair program that checks for file damage and boot sector problems, but it doesn't boot from the HD into Windows. I even tried removing the new video card and the 54g PCI card, and using the onboard AGP 2x video in the motherboard, and same thing. I noticed when it starts up it querries the two HD's and the two CDROM drives and the green lights on the CD drives go on briefly and then go out, and the BIOS also recognizes the 4 IDE drives just fine (10gb HD is master, 2gb data drive is slave and one CD is master and the DVD/CDRW is slave). But the floppy disk green light stays on. I tried unplugging the floppy and booting, and even disabled the floppy in the bios, no help. I even disconnected the two CDROM on the secondary IDE as well, so all I had were the 2 HD's and no help. I also disabled the second serial port and the parallel port in case of IRQ conflict. Win 2k should boot up and recognize the new motherboard and re-install the right drivers, right? What should I do next, to avoid reformatting and having to re-install win 2k, all my applications and all my drivers from scratch? All my data is on the second HD, except for my outlook data file, scanner data, and I copied them over to another computer since the second HD is full.