Windows 2008 Server Standart VM won't shrink D drive as available space

Hi all !!

Here is my problem actually ! Hope I'm clear enought !

SETUP :
-HYPERV : Server 2012 R2
-2 ARRAYS : RAID5 10K 1.6TB  &  RAID10 15K 800GB
-CONTAINER : Controller IDE VHDX 830GB  located in the  RAID5 10K
-VM : Windows 2008 Server Standard with a 160GB C: drive  and a  830GB D: drive

PROBLEM :
- Moving a 830GB VHDX into a 800GB container
- In the VM Win2008 the D drive usage is 515GB free out of 830GB
- In HyperV Manager the VHDX file says 770GB used out of 830GB
- In the VM Win2008 the Disk Shrink won't let me shrink more than 990MB ???

ACTIONS TAKEN :
- Removed pagefile for the D drive
- Performed a Defrag
- Set Write Debugging Information to NONE
- Defrag again
- Installed Smart Defrag to see the map and no unmoveable file are at the end of the volume...

Any suggestions would be very appreciate !!!