You can partition and format the drive with the WinXP installation disk. You can also use the Seagate DiscWizard program to partition and format the drive. There is no need to convert the drive. Just format as NTFS.
http://www.seagate.com/www/en-us/support/downloads/discwizard
http://www.seagate.com/www/en-us/support/downloads/discwizard