Maybe this would help
Boot XP using your old Maxtor HD make sure that ur new Seagate HD is installed too.
Download Disc Wizard (software from seagate).
http://www.seagate.com/support/disc/utils.html
It's easy to follow the steps just choose how much space you want to format and what type of partition you want then a restart is required after choose the setting you want, the reason of this is to install a patch to your PC to enable you to support/format your HD past 137GB. The set-up will continue after your restart, then the formatting process will undergo completion. You have now successfully formatted your new Seagate HD.
You can now install XP on your new HD without worrying that additional 150GB you've wasted on your new HD.
USE NTFS to support larger that 137
Trying my best to help, BTW I'm only 15, sorry if this is too noobish for you, but it's the easiest way though.