Related to the "setup cannot delete specified partition" , U can also try formating, deleting or adding a partition with the recovery console.
Boot from win cd, press r, 1, enter (or type password)
format X:\ /q
(X is the drive U want to format)
Deleting or creating a partition:
for that you have the diskpart command.
If that doesn't work, I agree with my upstairs neighbour.