I have a Toshiba 40 GB hard drive, model # MK4025GAS, 4200 rpm, that no longer works. I'd like to purchase a new hard drive for my HP Pavilion ze 4900 laptop. I'm not sure whether my current hard drive is designed to work under the "ATA-6, "SATA 3.0 Gb/s" or the "Serial ATA-150". I understand that I need to know this in order to purchase a hard drive that will properly work w/my laptop. I'm also curious to know what space and speed I should upgrade to.