Change the option "First Boot Device" from BIOS as "CD ROM"
So it will boot from XP CD that one you inserted.
When it boots from that CD it will show you first Repair option " you have to press R button there.
Then wait it will show you C partition somwthing like this C:\windows :
Then try to go the CD Rom partition that may be E: or F: etc
if its E drive for CD ROM It will be like this:
now in that type DIR
it will sho you all the contents from CD
E:\ cd i386
E:\i386\ : expand system
for safer side if there is any other file called system i.e. system.DL_ or system.DLL
I think there are 5 files start from system expand all those files
type the same for those files
E:\i386\ : expand system.DL_
E:\i386\ : expand system.DS_
after you done type exit & it will reboot...no need to boot from CD then
it should solve your problem.
if not then reply!!!