Because Disk Management cannot move Unallocated space or make Unallocated space on the left when shrinking partition, you have to run third party software. If you want to merge Unallocated space to C drive, you must move Unallocated space next to C drive in advance. Therefore, Extend Volume is greyed out for both partitions. You cannot get such required Unallocated space with Disk Management, because it can only make Unallocated space on the right when shrinking a partition.įor example, after shrinking D drive via Disk Management, Unallocated space is made on the right of D, it is nonadjacent to C drive and is on the left of another E drive.
Because to extend a partition with Disk Management, there must be contiguous Unallocated space on the right. Windows 10/8/7 Disk Management has Shrink Volume and Extend Volume functions to help you resize partition without losing data, but it cannot help you extend a volume by shrinking another one. Disk Management can't move Unallocated space to the left
