Dual Boot Problem

[Fideen]

Hi,

I have had this system dual booted before, but I upgraded one of the operating systems to a different version and now only one will boot.

what I have:

1xHDD partitioned with 70gb each. Drive C:\ is Windows Vista and Drive E:\ is XP (drive D is a storage harddrive for all the downloads and music etc.

initially i had vista 32bit installed and xp pro and it was working fine. then I did a fresh install of windows Vista 64bit over the 32 bit (formatted the C:\ partition). all seemed well, I then tryed to set up the dual boot through vista using EasyBCD v1.6 (because xp does not show on startup). added the xp pro to the Entries (now both show on startup in the dual boot screen) but xp didn't load...corrupt or missing \ntldr, so i found on the net to copy ntdetect.com and ntldr fron xp cd to xp dir. tryed this 2 ways..

1. ntdetect.com; ntldr are on c:\ (vista partition) boot for xp pointing to c:\. Error is <windows root>\System32\ntoskrnl.exe please re-install this file.

2. ntdetect.com; ntldr are on E:\ (xp) boot for xp pointing to E:\. System restarts with no error.

yet xp loaded perfectly fine before i changed from 32-64.

should I re-install the ntoskrnl.exe? if so from which disk (xp or vista)?

Thanks