To make unused disk space available, you can decrease the size of a volume by shrinking it—without having to reformat the disk. For example, you might shrink a partition if you have one disk partition that has a large amount of free space and you need a new partition for a different purpose, such as installing a second operating system for disaster recovery.
You can shrink partitions either from the Disk Management snap-in or from a command prompt using the DiskPart command.
There are certain restrictions on the types of partitions that can be shrunk in this way. The restrictions and steps for shrinking a partition are slightly different for basic volumes and for simple or spanned volumes.
For more information about shrinking a basic volume, see Shrink a Basic Volume.
For more information about shrinking a simple or spanned volume, see Shrink a Simple or Spanned Volume.