I installed both Windows 2003 and Win2K on my home PC's hard disk. I wanted to be able to dual boot both OSs, but I discovered that if you install Windows 2003 first on a separate partition, you aren't able to dual boot. You can boot only to Win2K.
Rather than uninstall and reinstall the OSs, I solved the problem by copying the Windows NT Loader (Ntldr) and Ntdetect.com files from the Windows 2003 CD-ROM to C:\. The latest version of these files can detect both OSs. Ntldr determines the location of the OS boot partition and launches Ntdetect.com. Ntdetect.com, in turn, obtains device and configuration information.
—James Lim
james_k_k_lim@apl.com