Maximum PC

I've just finished copying a large quantity of files to 2 identical new 2TB WD Caviar Green hard drives, yet Windows 7 is reporting that the two drives have a 35GB difference in "Free Space".

The drive Properties>General tab "agrees" on the drive capacity, the number of folders, the number of files and the amount of Used Space.
But Properties>General tab reports an approximate 35GB difference in "Free Space" -- and so does Computer>Manage>Disk Management.

The System folder shows as 0 Bytes.
I have emptied the Recycle Bins on both drives -- and they show as empty.
The Properties>General>Disk Cleanup -- indicates that there's nothing to cleanup.
Recycle Bin is set to the same capacity on both drives, and there is no paging file on either of them.

I ran Crystal Disk and it is reporting that the drive with the lesser capacity, which is internal, is still good. The second drive, which has the "extra" capacity, is connected via SATA dock on my case (Corsair 650D) and is not showing up in Crystal Disk, but file transfers/etc have no problem with the drive.

Anyone ever see this before -- or have an explanation for why this is happening.

Thanks for your input.

the only thing i can figure is hidden files... Try using windirstat, http://windirstat.info/ this will give you breakdowns and you can compare that way, you are right... thats a large difference, Could be something like (Filename too long) especially temp files things like that sometimes have issues transferring

Could be that windows is adding/managing your pagefile and either your sys state(registry) has increased in size, and or the same for the pagefile sys. Is your mem handled by windows on both of the drives? Just a thought....