vista/xp pro x64 dual boot problem

I just recently installed Vista 32bit on my computer. I installed it to a
separate physical hard drive as to not conflict with my previously installed
XP Pro x64. I get to the boot OS selection, and I select Vista, and it boots
fine. I select XP and I get the following error:
Windows cannot start:
WINDOWS\system32\ntoskrnl.exe missing or corrupt

I have tried all solutions to this problem on Microsoft's web site,
including using the repair console to replace the file. I am not able to see
if the boot.ini file is correct because I cannot boot into XP. I also tried
the bootcfg/rebuild solution in the repair console, and that failed. Any
help to remedying the problem would be much appreciated, as I need that
version of XP working.

My system is the following:
Pentium 4 2.8 GHz
BFG nForce 680i SLi
BFG GeForce 6600 x2 in SLi
3GB physical RAM (2 of which vista recognizes)
Vista and XP on separate HDDs