Question about debugging BSOD mem dumps

I had a thread going where I could not determine the cause of a mysterious BSOD here http://forums.majorgeeks.com/showthread.php?t=159628 As suggested, I was going to try and debug the memory dumps (using the steps here http://forums.majorgeeks.com/showthread.php?t=35246) but it seems that you need to boot into Windows to do this, right? How would you debug memory dumps from a PC that doesn't load to the Windows XP desktop? The PC in the thread I linked to above is crashing to a BSOD right before the desktop loads in both safe mode and normal mode... any ideas? Can I run the debugger process from either a command prompt or a PECD or the UBCD4Win?

Thanks!