This is what you need to do once you have it physically installed...
1. Boot up windows xp (assume this is what you have)
2. Start - settings - control panel
3. Administrative tools
4. Computer Management
5. Disk Management
You should see the unpartition hard drive. Go from there. Right click on the drive, partition, format and assign drive letter.
edit: pkme2 beat me to it. 😀