1: i see your computer has sata, just sort the drives by anything sata.
2: groundrat didnt even take the time to google an Inspiron 518 he actually suggested an SSD and thinks you have a laptop.
Id just go with some cheaper seagate drive, like a barracuda... matbe a WD. you would want to look at the 3.5 inch drives. http://www.newegg.com/Product/Product.aspx?Item=N82E16822236339
There's one for reference, they're dependable.