Good disk tools for bad sector scanning?

[Gannon]

Anyone know some good disk tools for bad sector scanning that can be used before the OS boots into XP? For dos I guess you could say.

 

[RadiclDreamer]

Gibson Research Corp makes a great program called spinrite

 

[Matthias99]

Also, most (if not all) hard drive manufacturers offer low-level scanning utilities you can run on their drives, which run before the OS loads (usually from a bootable disk/CD). Check your manufacturer's website/documentation.