Increase C drive space by reducing D Drive space in Windows11

Question

Need help in increasing C drive space from D drive in Windows. I have freed up 400 GB from D drive, however, I am not able to allocate that memory to C drive. Can you please help me solve this issue. in Disk management, extend volume is disable for C Drive where as extend volume is enabled for D drive.

Answer 1

Hi Prasad RLN,
Welcome to Microsoft Q&A forum. I'm happy to help.

For your task, you should use a third-party application such as MiniTool Partition Wizard to achieve.

Disclaimer: Microsoft provides no assurances and/or warranties, implied or otherwise, and is not responsible for the information you receive from the third-party linked sites or any support related to technology.

Please note that partition C and partition D have to be on the same physical disk to do so.

If you have any difficulties in any steps, please feel free to let me know.

---

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

Answer 2

Windows has limited partitioning ability, it can only extend a partition into a space that is directly to the right of the partition to be extended.

I need to see the partition table on your drive(s) to be able to provide you with a solution.

Open Disk Management, then expand the bottom pane so all drives and partitions are visible in that pane, please provide a screenshot of the Disk Management window.

Answer 3

In Disk Management, a volume can be extended only into unallocated space that is directly adjacent to it on the right. The C drive cannot use free space that still belongs to D or that is separated from C by another partition.

To use the 400 GB freed from D for C:

1. Open Disk Management
   • Select Start, type disk management, then select Disk Management.
2. Check the partition layout
   • Look at the bar for the disk that contains C and D.
   • Confirm whether there is Unallocated space immediately to the right of C, or whether D (or another partition) is between C and the unallocated space.
3. Make the unallocated space contiguous with C
   • If the 400 GB is still part of D (D is just “emptier”), shrink or delete D so that the 400 GB becomes Unallocated space.
   • If there is any partition between C and the unallocated space, that partition must be moved or removed so that the unallocated space sits directly to the right of C.
   • This may require:
     • Backing up the data on the partition(s) between C and the unallocated space, then deleting those partitions in Disk Management, or
     • Using a third‑party partition tool to move partitions.
   • Always back up important data before deleting or moving partitions.
4. Extend C into the adjacent unallocated space
   • Once the unallocated space is directly to the right of C:
     • In Disk Management, right‑click C and select Extend Volume.
     • Follow the wizard to add the unallocated space to C.

If Extend Volume for C is still disabled, it means there is still no unallocated space immediately next to C on the right, or the space is not correctly assigned as unallocated.

---

References:

• No Extend Volume command for drive C in Disk Management
• Extend a basic or dynamic volume