If you want to leave no trace of vista or anything that is currently on the computer, choose
Format the partition using the NTFS file system (Quick)
or
Format the partition using the NTFS file system
if you want to leave the files that are currently on it, choose:
Leave the current file system intact (no changes)
The last option will leave you with a slightly messy hard disk, so if there's nothing you need, I would go with NTFS or NTFS (Quick) NTFS will take significantly longer than quick, but either should work.