If all your looking to do is completely wipe the drives and start fresh, try this:
From the partition setup screen during the Vista install process, press Shift + F10. This will bring up a command prompt. At the command prompt, type
Dispart will start and you'll be presented with the diskpart "prompt" of DISKPART>. At the prompt, type
Note the disk number of the drive you want to wipe. At the DISKPART prompt, type
Code:
SELECT DISK [I]YOURDISKNUMBER[/I]
You'll get a message saying that Disk x is now the selected disk. At the DISKPART prompt, type
This will erase all the configuration information, including data, partition tables, MBR, etc from the disk!!
This will leave the disk in an "uninitialized" state and must now be partitioned. The disk should still be selected, so at the DISKPART prompt, type
You can also create other types of partitions using this command by swapping out "PRIMARY" for "EFI", "EXTENDED", "LOGICAL", and "MSR". If you use primary, it will simply create one large partition that fills the disk.
That should get you started. Diskpart is a very powerful tool though, so definitely type HELP at the DISKPART prompt for a full list of commands. you can also type HELP COMMANDNAME to get detailed info about that command.