Access your device manager and ensure it is installed properly.

• To access the Device Manager on Windows 7 and Vista, click on Start and type in "device manager" then press enter.  Double click on Universal Serial Bus controllers.  Ensure that the USB Mass Storage Device is listed without any yellow question marks or exclamation points.
• To access the Device Manager on Windows XP, click on Start>Run and type in "devmgmt.msc" then press enter.  Double click on Universal Serial Bus Controllers.  Ensure that the USB Mass Storage Device is listed without any yellow question marks or exclamation points.

If you are attaching a brand new hard drive please ensure you format it.