cant get into windows missing file

[untilted]

i was just at my friends house sorting out his computer, all i was doin
was arranging files cleaning out folders ect, i must have deleted
system file or something becuase after i restarted the computer it gav
me this message,:

file NTLDR missing press CTRL ALT DELETE to restart windows

ok so i tried fixing this by putting in the windows xp disc and the
restarting, it would not read the disc, it just went back to th
message, so i tried to get into bios to sort it out, but i dont kno
which key i have to hit to enter bios it doesnt say

by accident i got into bios i dont know how, then it asked me for
password, we have never setup a password for bios.

the computer was bought from an independant computer shop, the gu
built the computer for us, he must have setup the password! or is ther
a standard password for bios?

im not very good at explaining things so if someone understands m
dilema i would be more than grateful for some help.

thank

 

[WTC]

i was just at my friends house sorting out his computer, all i was
doing
was arranging files cleaning out folders ect, i must have deleted a
system file or something becuase after i restarted the computer it
gave
me this message,:

file NTLDR missing press CTRL ALT DELETE to restart windows

An NTLDR or NTDETECT.COM Not Found Error
http://support.microsoft.com/?kbid=555304