Almost out of space on D drive. I shrunk C drive size by 5GB which is unallocated. But when I do to Disk Management and try to reallocate those 5 GB to D drive, it shows "Extend Volume" is greyed out so I can't extend size. Please help. Thank you.
Windows built-in disk management can only extend a volume when there is an unallocated space contiguous behind. In your situation, you need to move the unallocated space behind D drive through third party partition software, eg, AOMEI Partition Assistant, Partition Magic,etc.
you can not use the unallocated space that is in the front of D to extend D, the unallocated should be on the right side and next to D and then you can use Windows build in disk management to extend that partition, this is the limitations of Windows build in disk management tool.
In addition, I'd like to recommend a free data recovery software called AOMEI Data Backuper that can used to create a recovery disk, in case of data loss, system crash, if you are not mind to get one copy of that software you can download it from CNET: http://download.cnet.com/AOMEI-Data-Backuper/3000-2242_.... currently this software is free
It sounds like the unallocated space is not adjacent to your D drive. That’s why the “extend volume” is grayed out.
But, that’s not to say, you have no other way to extend your D drive space.
You do can try some partition resizing tool instead.
Here is a video tutorial that may give you some help: https://www.youtube.com/watch?v=6jCeT7CbsKk
Of course, never forget to save all important data well all the time.