zorphnog, Thanks for the suggestion. Indeed I don't think that is the issue. I've now discovered that chkdsk (while windows is running, not PE), shows a problem with $Bitmap, and when I do an offline defrag (in PE), the defragmenter can't move that file. What is interesting is the position that file is located looks to be the same position I can shrink the disk to. Looks like diskpart querymax is seeing the 19GB, but can't shrink beyond this file which is located at the 9500MB from the end of the disk, the point that I can shrink to. I suspect there is something corrupt with this file. I've tried chkdsk /f in the OS, and rebooting, but then the issue reappears. I've read a few things around defragmenting the MFT to fix this. Does anyone know of an MS / or freeware tool that uses the MS API, tool that will do this? Thanks