To a brand new hard disk, you need to initialize it, then create and format partition with a file system. To use disk space and organize files more efficiently, you'd better create several volumes in a hard disk. But on the contrary, the more partitions in a disk, the less space in a partition, so the partitions are more likely running out of space, especially to system partition C.
In that case, nobody likes to start from scratch to reinstall Operating System and all programs. It also costs a long time if back up, delete and recreate partitions, and then restore everything. In Windows computers, you can extend partition without losing data.
To extend partition in Windows computer, you may either use Windows built-in tools or 3rd-party partition software.
Windows has 2 native tools to help extend partition - Disk Management and DiskPart. Disk Management is a built-in component with graphical interface. DiskPart works via command prompt. The benefit of these native tools is safe (in most cases), but because of many limitations they cannot extend partition by shrinking other volumes.
Remember to back up or transfer files before extending partition with either native tool, because a partition must be deleted.
How to extend system partition with Disk Management:
How to extend system partition with Diskpart command:
There's another Shrink Volume built in Disk Management, why not extend partition C by shrinking D? Because Extend Volume function and diskpart extend command only works when there's contiguous Unallocated space on the right, Shrink Volume cannot produce such required space. In some cases, you still cannot extend C drive even by deleting the right contiguous partition, learn why Extend Volume greyed out in Disk Management.
With NIUBI Partition Editor there are no such limitations, and you just need to drag and drop on the disk map. If you use Windows 10/8/7/Vista/XP home computer, there's free edition.
No matter you want to extend system partition or any data volume, it should be done inside a disk. No software can extend a partition by adding or transferring space from another separated disk. In most of Windows servers and PCs, there's free space in other partition(s) on the same disk. For example, if you want to extend C drive, you can shrink D or other volume on the same disk, then part of free unused space will be converted to Unallocated space, finally add Unallocated space to C drive.
By this way, Operating System, programs and anything else keep the same with before. Better than Disk Management and diskpart command, NIUBI Partition Editor can make Unallocated space on either left or right side while shrinking partition.
How to extend partition with NIUBI Partition Editor:
If you want to extend a nonadjacent partition, there's an additional step to move Unallocated space. Follow the steps in the video:
As I said above, no software can extend a partition by adding space from another separated disk, then what to do if there's no other partition or entire disk is full? To a physical hard disk, you need to clone it to a larger one, follow the steps in the video:
To any types of hardware RAID array, or VMware/Hyper-V/Virtualbox virtual disk, there's no difference if there's available free space on the same disk, simply follow the steps above to shrink and extend partition.
Different with physical hard disk, if entire virtual disk is full, it is much easier and you can expand virtual partition without cloning to other disk.
No matter how your disk partition is configured, there's a way to extend a partition with NIUBI Partition Editor. Select the corresponding method according to your own disk partition structure. Better than other tools, NIUBI has 1-Second Rollback, Virtual Mode and Cancel-at-well technologies to protect system and data. It is also 30% to 300% faster because of its special file-moving algorithm. Besides shrinking, moving and extending partitions, it helps do many other operations.