Inspiron 1100 HD prob.

I knocked my Insp. 1100 on the floor.:smileysurprised: I sent it to Dell, they sent it back. Need a new hd. OK, go to BestBuy, buy a new 80gb Seagate hd. Go to install. Pin arrangement is different. There is a "jumper" (Dell calls it an edge connector) for lack of a better word, which won't fit the Seagate hd. The OE hd is a pin-type arrangement, the Seagate is not the same.  Box for new hd says "Serial ATA".  Is this the wrong hd? Do I now have to eat this (box is opened, I assume BB won't take it back) and buy another hd? I hate computers.:smileymad:

Kurt