1TB my book says its full but there`s only 480 gig on there?

Hi - I bought a 1TB my book about 2 years ago and filled it up to around half way and it kept saying it was full at about 480 gig and wouldnt let me copy more data on, I thought it might be a back up file issue although I couldnt see where the back up data was so i copied everything onto another hard drive and formatted it.
It said 931 gig free and i thought everything was ok except now Im back up to around half way and it says its full again? There`s none of the original wd software on it, any help on how to fix it would be much appreciated.

  • Gabe

Do you get this problem using WD’s software (Smartware), using Windows backup or just normally copying clean files with no software?

what operating system are you using this drive on?