Dell GX620 and SATA 250 GB Hard drives - XP install doesn't see the whole disk

I so hate to ask a dumb question - but any help would be appreciated.

 

Received a new GX620 with two 250 Gb SATA disk drives.  Needed a "standard" copy of XP installed so I began the installation, deleted the C: partition, and tried to reformat the disk.  However, the largest partition I could make was 131Gb.

 

Anyone have any ideas on how I can get XP to "see" the rest of the disk?  Shades of NT4!

 

The onboard system diagnostics don't see any problems.  Also the BIOS correctly reports the disks (1 and 3) as having the correct size.

 

- thanks much,

 

  Matt