I'd suggest installing it as an internal drive, you don't even need to screw it in the case, just connect the cables, and format it. Then install it in the case. It's possible this wouldn't be necessary, you put it together and it works, but if it's not recognize, you'll spend time troubleshooting and could end doing the above anyway.
Not very much info here. What windows are you using? I'm assuming XP. Plug into computer, windows should recognize it automatically. Go into My Computer and see. If so, right click on it and them format using NTFS. If it's not in My Computer, go to Control Panel/Performance and Maintenance/Administrative Tools/Computer Management and then Disk Management. There will be a drive with un-partitioned space there, make your partition(s) and then format. Hope this helps.
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