|Usually you can only attach them one way. For the older IDE drives with the 40-pin connections one of the pins on the drive is missing. That matches up to a filled in pin hole on the wire harness. If the harness doesn't have the filled in hole you can figure out the alignment by looking closely at the edges of the cable. One side will have a red stripe along the length of the cable. That is the # 1 pin side. So you attach that side to the # 1 pin side of the drive and the motherboard. On all the hard drives I've seen the # 1 pin side is the side closest to the power connector. If you have any doubts at least some of the pins will be numbered on the bottom of the drive by the connector.|
The power connector also fits only one way. The ends of its connector are notched on each end of one side and that matches up to the connection on the drive.
Sata drives have different connections but they too only fit one way.
If you need additional help, post back the drive model number and we can find some pictures.
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