Reinstall the hard drive in the laptop. Put the drive in the system as shown. Push the drive forward to lock the drive in. Once you do this, screw the drive in the laptop.

If you are using an SSD, you will need a 7mm to 9.5mm adapter. A lot of SSD's include this, but you may have to buy one. You can stick this in the chassis of the laptop or on the drive. Note: All modern SSD's are 7mm. Hard drives are either 7mm or 9.5mm. If you are dealing with a spinning drive, a 7mm-9.5mm adapter may not be an option.