Cloned to a larger SSD, but C: is still the old size
Windows boots and your files are there, yet Extend Volume is grayed out. Can you use the extra space without starting the migration again?
A successful clone does not necessarily enlarge the Windows partition. Kingston explains that cloning software may leave unused space when it copies to a larger drive without scaling the partition size. Your operating system can boot from the new SSD while C: still has the old capacity. Kingston's capacity-after-cloning FAQ
One user replacing a 500GB HDD with a 1TB SSD found the same free-space figure after cloning. Extend Volume was unavailable, and the user asked whether New Simple Volume would help. That option creates somewhere to save files while leaving C: at its existing size. To enlarge an NTFS C: on a Windows 11 basic disk, Disk Management needs unused, unallocated space immediately to its right on the same disk. Dynamic disks, RAID and Storage Spaces use different configurations, so this extension procedure does not cover them. The original migration question
931GB and an undersized C: are different problems
Three numbers can appear to disagree: the capacity on the SSD's packaging, the total size of C:, and the free space within C:. They measure different things. A 1TB product does not promise that an installed Windows system will leave 1TB free for your next files.
The unit calculation explains part of the apparent discrepancy. One decimal terabyte is 1,000,000,000,000 bytes. Divide by 1,024 cubed and the result is approximately 931.32. The binary unit is properly called a gibibyte, or GiB, although Windows capacity displays can label that number GB. NIST's binary and decimal unit definitions
| Advertised decimal capacity | Conversion to GiB |
|---|---|
| 500GB | Approximately 465.66GiB |
| 1TB | Approximately 931.32GiB |
These are unit conversions, not measurements of a formatted volume. Other partitions and formatting affect the final layout. You do not need to recover a missing chunk merely because a 1TB drive appears as roughly 931GB. But if that disk contains an old-sized C: and a large unallocated area, the latter is real capacity you have not assigned to a volume.
A Windows 11 support question combines both concerns: why a 1TB SSD shows 931GB, and why Extend Volume is unavailable despite unallocated space. Explaining the units answers the first question; it does not resolve the second. Microsoft Q&A example
The SSD's capacity and partition layout
Right-click Start and open Disk Management. In the lower pane, locate the row for the new SSD and read its overall capacity alongside its partitions. Unallocated space appears with a black bar. It belongs to the disk but has not been assigned to the existing C: volume.
If the original drive is still connected, check the disk's model in its properties and identify which disk contains the current C:. Do not assume Disk 0 is the replacement. Kingston's boot-drive guidance also calls for checking which drive is selected after cloning. If the PC still boots from the original, its C: will naturally remain the old size.
These hypothetical layouts show three possible partition orders:
Layout 1: [EFI, etc.] [C: NTFS] [Unallocated]
Layout 2: [EFI, etc.] [C: NTFS] [Recovery] [Unallocated]
Layout 3: [EFI, etc.] [C: NTFS] [D: Data] [Unallocated]In layout 1, Extend Volume can add the unallocated area directly to C:. In layout 2, the recovery partition blocks that extension; in layout 3, D: blocks it. On a basic disk, the space must be immediately to the right of the volume being enlarged and on the same disk. Unallocated space on another disk's row cannot be added to C: through this procedure. Microsoft's basic-volume documentation
If the entire physical disk reports far less than expected and there is no unallocated area, record its model, reported size and connection details for manufacturer support. Repeated attempts to extend a partition will not explain why the underlying device is reporting the wrong capacity.
Extend C: when the space is directly beside it
Have a separate backup of important files before changing the layout. If you have edited documents on the new SSD since cloning, the old drive may no longer contain their latest versions. Check that those newer files can be opened from the backup location.
- Open Disk Management with administrator permissions and identify C: on the new SSD.
- Confirm it is NTFS and the unallocated region is immediately to its right on that disk.
- Right-click C: and choose Extend Volume.
- In the wizard, choose how much of the available space to add. You can use the maximum or leave some for another volume.
- Review the target and size, then complete the wizard.
If the menu remains unavailable, recheck permissions, file system and position. Microsoft's extension instructions specify those requirements. This operation adds an already unallocated region to the volume; it does not require formatting C:. Extension requirements and wizard
Deleting files is a different operation. It increases free space inside the existing volume while keeping the volume's total size unchanged. If the migration preserved a smaller C:, cleaning Downloads will not allocate the rest of the SSD to it.
When a recovery partition blocks the way
In layout 2, Windows cannot extend C: across the recovery partition. That partition supports Windows recovery; the EFI system partition supports booting. Neither becomes disposable because it lacks a familiar drive letter in File Explorer. Microsoft's UEFI/GPT partition layout
To make C: larger in this arrangement, you need a layout change that preserves the required partitions, or a new clone configured with a larger target Windows partition. Disk Management does not provide a drag-and-drop move for the recovery partition. A partition-moving tool must support the actual file system, encryption and layout; availability of a Move button alone is not enough to select one.
Recloning also needs a current source. Files created on the new SSD since the first migration may not exist on the old drive. Preserve those changes before making the new SSD a cloning target again. When the cloning tool provides a target-layout preview, inspect the proposed C: size before starting; merely repeating the original settings can repeat the original result.
If your immediate need is room for documents or video, a separate volume after the recovery partition can use the space without moving it. If Windows or an application specifically needs more room on C:, another drive letter alone does not solve that requirement. Decide based on where the files or application must actually be stored.
Use the remaining space as a separate volume
Right-click the intended unallocated region and choose New Simple Volume. Select a size and an unused drive letter. For a Windows data volume, review the NTFS format and volume name, then finish the wizard. Confirm you are creating a volume in empty space, rather than formatting an existing partition containing files. Microsoft's new-volume procedure
The result might appear as E: in File Explorer. You can save files there, while C: remains its existing size. Creating E: also means that region is no longer unallocated space ready to add to another volume. It is an alternative use of the capacity, not a preparatory step that automatically unlocks Extend Volume for C:.
C: and E: on the same SSD are not separate storage devices. Copying a document between them does not produce protection against that SSD failing. The practical benefit is a new storage location: select it when saving files or configuring applications that allow a different data path.
For a larger drive that cannot use capacity beyond about 2TB, inspect the partition style under the disk's Properties → Volumes tab. MBR/GPT is a separate branch of troubleshooting. Microsoft's ordinary Disk Management conversion procedure requires removing existing volumes, so it is not a harmless toggle to try on your populated drive. It is also unrelated to the normal 1TB-to-931 display conversion. Partition-style inspection and conversion conditions
Check the result before reusing the old drive
Return to Disk Management and inspect the target volume and remaining unallocated space. In File Explorer, compare both total capacity and free space. If you created a separate volume, confirm its drive letter and save and reopen a file there.
A larger total capacity with less free space than expected may simply reflect the Windows installation, applications and files already present. An unchanged total capacity calls for a different check: did you inspect the original disk, or assign the extra area to a separate volume instead of C:?
Keep the original drive until the replacement boots correctly and the files you need open as expected. If you request support, include the product capacity, new SSD model, whole-disk capacity, C: size and partition order. That gives the technician the information needed to distinguish a unit conversion from a layout left behind by the clone.