If you were not "across the pond", I'd say ship one of the drives to me and I'd work out how to do it and send it back to you...
I love SOLVING such technical puzzles.
The work leading up the solution, not so much...
What I'd recommend is first look for ANY Windows XP (OR Vista) installation disc and using a computer WITHOUT any other drive connected, boot from the XP installer disc
and use that to delete the existing partitions and format the drive.
a Windows7 installation disc will invariably create a partition 100mb smaller than specified with an unlettered 99Mb "System Reserved" partition at the front of the drive.
Windows XP, Vista & 7 will allow FOUR primary partitions on a single hard drive, however Vista & 7 will only allow the creation of THREE primary partitions.
XP will actually create FOUR.
What Vista & 7 will do when attempting to create the fourth is to create an "Extended" partition nested inside a "Logical Drive" and I've found
these tend to be unstable.
So even after the loss of support for XP there is still a use for having a dedicated
"OLD" computer running XP as a "Formatting station" and keeping an XP installer disc around simply to use as a formatting tool/partition deleter.