Was the new install a clean install or was it over the previous setup? If
you installed over your previous OS and it was Win2K as indicated, was it
workstation or Server? I don't believe Win2K is a valid upgrade path to XP.
If this error is appearing during setup and you are installing over Win2k,
are you sure your privileges in Win2k are set at a level that would allow
this installation. If not, it might be blocking install.
There is a knowledge base article on this issue but it applies to Win2K
http://support.microsoft.com/default.aspx?kbid=300038
Where are you getting the error, is it during setup, is XP already
installed, I assume the error prevents you from getting to the XP desktop,
if yes, where in the boot process does the error appear?