When you create an alternate install of Windows 2000 on a computer running Windows XP, you are no longer able to start Windows XP. When you select if from the boot menu, you receive:
Windows 2000 could not start because the following file is missing or corrupt: \WINDOWS\SYSTEM32\CONFIG\SYSTEMd startup options for Windows 2000, press F8.
You can attempt to repair this file by starting Windows 2000 Setup using the original Setup floppy disk or CD-ROM.
Select 'r' at the first screen to start repair."
If your Windows XP was an upgrade from Windows 2000, you may blue screen with:
The Windows 2000 bootstrap loader does not know how to load Windows XP.
NOTE: The Windows XP bootstrap loader knows how to load all previous Windows operating systems.
To fix the problem, start the computer in Windows 2000 and copy the files from the Windows XP CD-ROM to the root of the system drive. Copy NTLDR and Ntdetect.com from the I386 folder.
NOTE: When installing multi-boot configurations, each operating system must be in a separate partition. The preferred installation sequence is Windows 9x (or WinME), Windows NT 4.0, Windows 2000, and Windows XP.