Have you got any documents or back up on it that you carn't loose ? if yes then I carn't advise but if you can Formatt it then I can. Funny, I had the same problem with a new Freecom 500GB Ext HDD last month. My model was the Black one with a designer name tag on it.
If you connect the HDD to the machine and turn on, then right click on My Computer and select from the drop down menu "Manage". Then, select Disk Management.
Then click on the right hand side where you see your Freecom HDD so its hightlighted and then select Format. Accept all the defualt and cary out the format on the Freecom HDD
I found out from Freecom a number of the drives were badly formatted when being shipped. You may have not realised but the actuall size of the drive would show lower than 465GB if it was a 500GB drive.