WDDIAG (western digital diagnostics) tool is a free download and will partition and even copy an old HD to a new one if necessary. The download will let you create a boot disk that runs a setup program.
For the mice, I suggest those little poison packets or peanut-butter flavored glue traps, although if you use glue traps you have to dispose of a live mouse that may attempt to bite if it's sick/injured, instead of a dead one.
Leaving a plate or shallow bowl full of beer on the floor can also kill mice as they tend to drink, pass out, and drown in the beer.