Hard drive didn't partition full 300gb

make sure to enable LBA (logical block addressing in BIOS), format using NTFS file system.

Maybe the rest of the space is there, but a drive letter has not been assigned and partition has not been created etc.

go to administrative tools -> services -> computer management -> disk management and look what it tells you.

also what are your computer specs?
some older comptuers CANT HANDLE more than 137 GB
same with certain windows versions ( if I remember correctly, windows98 ,98Se and ME dont support higher than 137 GB )

You need Windows XP SP1 and a Bios update (maybe):

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

I downloaded windows xp sp2 and completley updated my computer. I built this computer myself and installed the HD before I installed the OS. Since it wasn't sure if I'd be using an OS capable of using the full 300gb it only formatted 137gb, but even after installing windows xp pro and sp2 with all the updates it still hasn't changed the HD size. What do I do from here? Thanks for your help.

Slipstream the SP2 to the XP, kill the partition, reload. If that doesn't work your BIOS needs an u/d.

You replied to my post about my hard drive, so i figured you could help. I don't know what slipstreaming is or u/d. By killing the partion and reloading is that the same thing as reformating? If I did that would I lose all the progams on my comp? Thanks for you help.