is there any way to restore rundll32.exe for windows XP? says it has the missing file "NVARCH32.dll" and so it cannot boot. says "Try re-installing the program to fix the problem" But how on earth do i reinstall it???

It is in your C: Windows/system32 folder. If you wouldnt have put a BS email address I would have emailed you a copy of it.

start > run > sfc /SCANNOW or expand X:\i386\rundll32.ex_ c:\windows\system32\rundll32.exe (fix paths accordingly, you might also have to do this one from safe mode?).

NVARCH32.dll is a NVIDIA executable. Rundll32 gives the error, but you have to reinstall NVARCH32.dll (that's the missing one, isn't it), not rundll32. Try updating your graphics card drivers. Yeahyeah i speak sh!tty english but who cares if the problem got fixed.