You need an internal drive - 2.5" 9.5 mm and parallel ATA, 120 G or smaller.  If it has no caddy, you will need that plus the blade adapter that fits on the back of the drive (the drive is standard but the latter two parts are Dell-only).

OK I just read the HTML DOC. That has the serv manual and according to it the installation is pretty straight forward.Just slide it into the bay and there you go.More or less.So what is this about blade adaptors??If I get a dell HD for this model it may come with this ? But if I get like a seagate 120G from an online type store or even at best buy I'll need this adaptor??

 Shoot the laptop was just 30.00 and won't be actually usin it as a laptop more as a desktop .

 I do have it now and so far the thing boots up the setup and I can read everything in the current system.I think Bios was a05.I'll have to check see if thats the latest update.The batts dead as dead can be.It's been in storage since the GI I got it from came back from the sandbox.So far the power supply works and everything else minus a HD is functional.

 Is there a linux section to this forum?I have a notion that maybe can use a linux kernall in the disc drive for an OS and an external HD thru a usb port or even potentialy maybe netwirk a portion of one my desktopd to the laptop for HD type storage.Just a mad thought.Playing DR.Frankenstien here.Any more thoughts ideas or suggestions??