Hello,
It sounds like your drive is toast! Have you spoken with Seagate support? I would not mention I dropped the unit, but they may be able to replace or service it at no cost under warranty.
Try some of the following tips to see if you can resolve it before contacting them,
-Make sure device drivers if needed are installed and up to date.
Click here for SG driver page 1) Power cycle the drive and Connect the drive and see if the light powers on. Touch the drive and see if you can feel vibrations letting you know it is spinning up.
If not spinning up,
2) Test the drive with a different USB cable.
*you can get a cheap one from a local store and return it after testing, unless it works then you can keep it*3) Test the drive with a different power supply, if possible.
If still not being recognized by windows, then I would recommend engaging Seagate Support. I have heard of these drives having this same exact issue, and ultimately a replacement is needed. Sadly, if your data is not backed up you will most likely lost it.
Click here for Seagate product returns pageRegards,
G33k