Recently my internal storage drive WD15EADS has been suffering from really slow write speeds. Before it would get 25-50 MB/s on very large files. Now its down to 1-10 MB/s. I did notice lagging when attempting to play videos or open folders on the drive. The drive is installed on a Windows 7 machine. I have tried it using on a XP box and as a external drive. The results are the same. I do have over half of the available space left. Is my drive going bad or is there anything I can do?