if the power and data cables are all hooked back up, is the boot process seeing the drive? (Turn off the stupid HP graphic screen, so you can see the bios messages) Did you disconnect the data cable then put it back backwards? Theres 40 pins, cable pin1 needs to line up with the connector pin 1 - red stripe on data ribbon cable, marking on drive cable connector port - line them up.
If all is connected and win isnt recognizing the drive it may be blorkt. Does the drive power up and spin up when the pc is booting?
Science, Mathematics, and Physics do not lie - only people do.