You shouldn't need drivers for a hdd, windows should install them automatically if it is able to communicate with the drive.
In device manager is there a yellow /!\ next to the device?
Could be anything from a bad cable to bad chipset drivers.
Try this:
First, please disconnect all USB devices and then perform the following steps:
1. Click "Start" button, type “devmgmt.msc” (without quotes) in the “Search” bar and press "Enter". Click “Continue” if necessary.
2. In Device Manager, double click to expand "Universal Serial Bus controllers", right click on the Host Controller, click "Uninstall" and click "OK".
3. Repeat the step 2 to uninstall all items under "Universal Serial Bus controllers".
Then, restart your computer and Windows 7 will reinstall all USB controllers automatically.