Please Help..Upgraded drive

hello all…I recently purchased a WD320 drive for my dell laptop.  This was to be an upgrade from my original 40g drive.  I am using a dell xps, with windows xp, with an update bios has been ran.

The new drive only shows a total of 40g…the same as my last drive.  I have been told that I need to set something to maxdrive size?

Thank u

Did you clone your old drive? Also, the drive shows the full size in the BIOS?