format a 500 gig ata Seagate drive

As you are limited to the Max size that BIOS can read.

You can use a Software utility to trick the BIOS but you will take a performance Hit or you can use a PCI to IDE Card which will not affect the performance too much as it will only limit your speed to that of the PCI Bus which should be very close to the On Board IDE Configuration. If you chose to go this way you'll need to make sure that the Controller Card that you buy will support a 500 GIG HDD as these have their own Firmware on them that act like BIOS and have a limit on the size of the drives that they can see.

One of the Promise Technology cards should work though without a problem but you'll need to look at the specifications of the individual PCI to IDE Card to get the right one.

Col

Windows XP classic has a problem with very large hard drives
The link below will tell you all about it

http://support.microsoft.com/kb/303013