D disk space and the actual size of the file does not

I have the D disk 19.5G, a document which has 11G of the remaining space 5.5G, the remaining space gone?
Less 3 G ah, I have no problem with the E disk space and the remaining space is the same The

system disk cache and D will bring the Recycle Bin take up space ..

you Hidden things open know we have a look at the D-ri site is not hidden files selection tool
you point at the click Folder Options to see there are a
Show hidden files and folders on the point of view
D look set to have hidden files to see if the cells, generally speaking, if only a few hundreds of M was normal, 3G can be a little on the abnormal