Question : boot disk in XP pro

I want to update the bios on my PC and I have to do it from DOS.  SO I made a boot disk and selected create dos boot disk when I formatted the disk.  so then i restarted with the disk in... It said loading then gave me the a: prompt.

When I tried switching it to c:    by the command C:  
it said "invalid drive specification"  

What other files do I have to put on that disk so that I can change from a: to c:.  and then continue to go into the directory and run the update for the Bios.  

By the way I have an MSI 845E Max (6566).  


Thanks
Andrew

Answer : boot disk in XP pro

You already have XP installed? then no, not worth it. that bios flash is if you are going to install XP, do it before the install