How to restore MBR / boot0

[Jörg Reisenweber]

Hi list,

I know the command how to restore the MBR ('fdisk -B -b /boot/boot0  
ad0), but know this stupid question of mine (Windows has overwritten  
the old MBR with its own): How do I manage to get to a working prompt  
with at least some useful commands such as 'mount' available? I tried  
the fixit shell from my 5.4-bootonly disk but that didn't help me  
very much. :/

Please help! :)

Jörg