Please help me asap

Ok so i have a seagate free agent pro 500gb external drive and my brother accidently wiped it when we were reinstalling windows. Now it will not mount as an external drive but windows still detects it when i plug it in as seagate freeagent pro drive.
Is there anyway that i can get back my lost data?
How should i go about getting windows to mount it as an external drive?

Please get back to me asap thanks

 

If that data is critical, there are companies that specialize in that sort of deal. It is quite costly. If you plan on going this route, unplug the drive immediatly to avoid overwriting your files.