When you use the harddrive upgrade wizard, it copies all the partitions and files on your existing stock drive to the new upgraded (larger) drive. This only equates to about 8 gig worth of space though. The harddrive upgrade wizard will then take the left over space on your new drive and use it to create f partition. If however you're upgrading to a very large drive (like 300 gig) where your F: drive will end up being greater then 237 gig, you have the option of splitting this space into an F: drive of 137 gig and a G: or whatever is left over after that.
I assume your upgrading from the stock drive, is that so? or have you done a previous upgrade and are ugrading agian?
As a final note, when using the HDD upgrade wizard, select the origianl drive as master, plug the new drive into where the DVD-ROM would be plugged in and set it to slave. Run the wizard and everything will be transferred and an additional F: will also be created. On the new drive this F partition will be empty as the stock drive has nothing that needs to be trasferred to this drive, in fact I don't think the stock drive even has an F: drive, I may be wrong though. once the upgrade is complete, remove the old drive, set your new drive back to cable select, create a 'games' folder on your F: and your good to backup games to your harddrive with DVD2Xbox.
Does that help?
i also recommend you get a copy of 'The Iceguide' if you don't already have it and it'll give you a detail approach on how to do all this. Just google 'The Iceguide'.