I got a problem. I have looked at many threads on this site but can't find one to match my problem so here goes. My kids computer (AMD 700Mhz, dual boot Windows XP/Windows 2000, 20Gb HD and 512Mb memory) stop booting to Windows XP. After starting, the Windows XP splash screen would display then disappear and a black screen would display and get stuck there. After several attempts of trying to boot in Safe Mode I got the same results. I can boot to Windows 2000 fine. My daughter had a file that she needed to finish and print urgently so I took the HD from their machine and connected it to my machine (AMD 3500+ 2.2GHz, Windows XP, 150MB HD raid0, and 2GB memory) to move the file and complete and finish it. After I shut down my machine and restarted it the next day I realized that I had the same problem with my machine. (I feel like such an *****) I should have run a virus scan on her drive and my machine but nooooo. Supecting a virus was at play, I then went to the net on my laptop to find the symptoms of the problem. Without much success I decided to use the Windows XP install disc to repair my Kid's computer. I initially tried to access the Recovery Console but can't get it to accept the administrator password. I then attempted to do a Windows Repair to fix the problem. This seem to be working fine as Windows Setup loaded all the required files. I then selected and hit Enter to set up Windows XP now. Clicked F8 to agree to the licensing agreement. I see the present Windows XP installation (C:\WINDOWS "Microsoft Windows XP Professional" is selected and click "R" to start the repair. Setup then starts the repair by examining the disk, then deleting and copy files to the HD and then reboots the system. Once it restart it then boots from the HD to Windows XP to complete the installation. I then get the popup lsass.exe - System Error that says "An invalid parameter was passed to a server of function". When you click Ok the system shuts down and reboots to start the cycle over again. And sadly I repeated all the above steps on the second machine and got the exact same results. Help... Any advice or assistance would be greatly appreciated.