Access to this page requires authorization. You can try signing in or changing directories . Access to this page requires authorization. You can try changing directories . Applies to: ✅ Windows Server 2025 , ✅ Windows Server 2022 , ✅ Windows Server 2019 , ✅ Windows Server 2016 , ✅ Windows 11 , ✅ Windows 10 You can add space to an existing volume by extending the volume into available unallocated (empty) space on a disk drive. This article shows you how to extend a basic or dynamic volume by using Disk Management or Windows PowerShell. Also learn about prerequisites, how to view unallocated space, and how to troubleshoot common issues that can prevent you from extending a volume. You can also use Azure File Sync to extend your volume into the cloud. For more information, see Planning for an Azure File Sync deployment on Windows Server . Before you extend a volume, make sure that you have the following prerequisites: Administrator permissions to open Disk Management or Windows PowerShell with elevated permissions. If you don't have administrator permissions, you can ask a member of the Administrators group to extend the volume for you. Administrator permissions to open Disk Management or Windows PowerShell with elevated permissions. If you don't have administrator permissions, you can ask a member of the Administrators group to extend the volume for you. Unallocated space on the disk drive that you want to extend. The unallocated space must meet the following conditions: The unallocated space must be located immediately after the volume that you want to extend. If there are any other volumes between the volume to extend and the unallocated space, you can't extend the volume. The unallocated space must be on the same disk drive as the volume to extend. You can't extend a volume across multiple disk drives. Unallocated space on the disk drive that you want to extend. The unallocated space must meet the following conditions: The unallocated space must be located immediately after the volume that you want to extend. If there are any other volumes between the volume to extend and the unallocated space, you can't extend the volume. The unallocated space must be located immediately after the volume that you want to extend. If there are any other volumes between the volume to extend and the unallocated space, you can't extend the volume. The unallocated space must be on the same disk drive as the volume to extend. You can't extend a volume across multiple disk drives. The unallocated space must be on the same disk drive as the volume to extend. You can't extend a volume across multiple disk drives. A basic or dynamic disk drive . You can extend a volume on a basic or dynamic disk drive. A basic or dynamic disk drive . You can extend a volume on a basic or dynamic disk drive. A volume formatted with NTFS or ReFS . You can extend a volume only if the volume is formatted with the NTFS or ReFS file system. If the volume is formatted with a different file system, you must first move or back up the files on the volume, and then reformat the volume with the NTFS or ReFS file system. A volume formatted with NTFS or ReFS . You can extend a volume only if the volume is formatted with the NTFS or ReFS file system. If the volume is formatted with a different file system, you must first move or back up the files on the volume, and then reformat the volume with the NTFS or ReFS file system. View unallocated space You can view the space utilization for a disk drive by using Disk Management. Select and hold (or right-click) the Start button, and then select Disk Management . If you can't open Disk Management, in the search box on the taskbar, enter diskmgmt.msc . Select and hold (or right-click) diskmgmt.msc , and then select Run as administrator . Select and hold (or right-click) the Start button, and then select Disk Management . If you can't open Disk Management, in the search box on the taskbar, enter diskmgmt.msc . Select and hold (or right-click) diskmgmt.msc , and then select Run as administrator . In the Disk Management window, you can see the disk drives and their partitions. The unallocated space on a disk drive appears as a black bar with the label Unallocated . In the Disk Management window, you can see the disk drives and their partitions. The unallocated space on a disk drive appears as a black bar with the label Unallocated . If you have multiple disk drives, you can select a disk drive to see its details, including the unallocated space. If you have multiple disk drives, you can select a disk drive to see its details, including the unallocated space. The following image shows the details for a disk drive. The unallocated space on the disk drive appears at the right and has a red border outline. Extend a volume To extend a volume, you can use either Disk Management or Windows PowerShell. Select the method that you prefer to use. Disk Management To extend a volume by using Disk Management, follow these steps.

In Disk Management, select and hold (or right-click) the volume that you want to extend, and then select Extend Volume . The Extend Volume Wizard opens. If the Extend Volume option isn't available, see the following section and check for volume extension issues to resolve. In Disk Management, select and hold (or right-click) the volume that you want to extend, and then select Extend Volume . The Extend Volume Wizard opens. If the Extend Volume option isn't available, see the following section and check for volume extension issues to resolve. In the Extend Volume Wizard, select Next . In the Extend Volume Wizard, select Next . In the wizard, under Select Disks , select how much disk drive space to use to extend the volume. The default approach is to use all available empty space ( Maximum available ) on the disk drive. If you plan to create other volumes in the available empty space, you can select a smaller amount of space to use to extend the volume. In the wizard, under Select Disks , select how much disk drive space to use to extend the volume. The default approach is to use all available empty space ( Maximum available ) on the disk drive. If you plan to create other volumes in the available empty space, you can select a smaller amount of space to use to extend the volume. Select Next , and then select Finish to extend the volume. Select Next , and then select Finish to extend the volume. To extend a volume by using PowerShell, follow these steps. In the search box on the taskbar, enter Windows PowerShell . In the search box on the taskbar, enter Windows PowerShell . Select and hold (or right-click) Windows PowerShell , and then select Run as administrator . Select and hold (or right-click) Windows PowerShell , and then select Run as administrator . Enter the following command to resize the volume to the maximum size. For the $drive_letter variable, specify the drive letter of the volume to extend. # Variable specifies the disk drive to extend $drive_letter = "C" # Get the partition sizes $size = (Get-PartitionSupportedSize -DriveLetter $drive_letter) # Resize the partition to the maximum size Resize-Partition -DriveLetter $drive_letter -Size $size.SizeMax Enter the following command to resize the volume to the maximum size. For the $drive_letter variable, specify the drive letter of the volume to extend. Check for volume extension issues If the Disk Management Extend Volume option isn't available, check your configuration for the following possible issues. After you address these issues, if you still can't extend the volume, try searching the Microsoft community - Files, folders, and storage site. If you don't find an answer on the site, you can post a question for input from Microsoft or other members of the community. You can also Contact Microsoft Support . Related content Resize-Partition Diskpart extend Was this page helpful? Need help with this topic? Want to try using Ask Learn to clarify or guide you through this topic? Additional resources Last updated on 2025-06-11