In Windows XP and Server 2003, when system C drive is running out of space, if you don't want to use 3rd-party software, you have to back up, recreate partitions and restore everything. From Windows 7 and Server 2008, Microsoft added new Shrink Volume and Extend Volume functions to help change partition size without losing data. However many computer users feedback that Extend Volume greyed out after shrinking volume D, so they cannot extend C drive. This article introduces why Extend Volume is disabled and how to enable Extend Volume option in Disk Management.
There are many reasons why Extend Volume doesn't work, open your Disk Management and find out your disk partition details, then you'll know the corresponding reason in your computer.
In most of personal computers and Windows servers, system C drive is formatted with NTFS by default. Therefore, if your system disk is GPT, reasons 1 is the most possible why Extend Volume greyed out for C drive. If you use MBR disk, check if the right contiguous partition (D) is a Logical drive.
If you shrunk drive D but extend C drive greyed out in Disk Management, there are 2 solutions with and without third party software.
Solution 1: delete the right contiguous partition
Note: the right contiguous partition D must be Primary, do NOT delete D if you installed programs or Windows services into it.
If you can delete the adjacent partition D, its disk space will be converted to Unallocated and behind C drive. Follow the steps to enable Extend Volume for system C drive:
Solution 2: move partition D and Unallocated space
If you cannot delete drive D or it is a Logical partition, Disk Management is useless, instead, you need to run third party software to move Unallocated space from right of D to the left.
How to enable Extend Volume option by moving Unallocated space:
There is free edition for Windows 10/8/7/Vista/XP home computer users.
To data volume, if it is a FAT32 partition, you may convert it to NTFS. You can also convert partition between Primary and Logical to enable Extend Volume. But with NIUBI Partition Editor you can shrink and extend these partitions directly. If Extend Volume greyed out because your MBR disk is 2TB+, convert it to GPT with NIUBI, follow the steps in the video:
Besides shrinking, moving and extending partitions, NIUBI Partition Editor helps do many other disk and partition operations. Better than other tools, it has innovative 1-Second Rollback, Virtual Mode, Cancel-at-well technologies to protect system and data. In addition, it is 30% to 300% faster because of the advanced file-moving algorithm.