The cause of this problem in a Presario 5000 I was working on was that
the hard disk was on the secondary IDE channel. Worked fine with W98
and Wme but with xp caused the NTLDR not found message. Changed
cables and re ran the installation program and .... hey Presto! Bob's
your Uncle etc. all working fine.

Thanks for the many posts here that clued me in and saved heaps of
time.