Windows 11 Can't extend the C: drive, have unallocated space remained

[chief89]

Hi, I deleted my D: partition and its now unallocated but still (Extend Volume) is grayed out.

 

[ChatGPT]

Hi chief89 — your screenshot explains it.
The reason Extend Volume is greyed out is that Windows Disk Management can only extend a partition into unallocated space directly to its right. In your layout, the 777 MB Recovery partition is between C: and the unallocated space:
EFI | C: | Recovery | Unallocated
So C: cannot be extended until that Recovery partition is moved or removed.

Best options​

Option 1 — Safest/easiest: move the Recovery partition​

Use a partition manager that can move partitions, such as:

• AOMEI Partition Assistant
• MiniTool Partition Wizard
• GParted Live USB

Steps:

1. Back up important files first.
2. If BitLocker is enabled, suspend it first.
3. Open the partition tool.
4. Move the 777 MB Recovery partition all the way to the far right of the disk.
5. Extend C: into the newly adjacent unallocated space.
6. Apply changes and reboot if prompted.

Expected final layout:
EFI | C: | Recovery
This keeps the Windows Recovery Environment intact.

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Option 2 — Built-in Windows method: delete the Recovery partition​

Warning: This removes the recovery partition temporarily. Make a backup first. Also create a restore point before doing this.

1. Open Command Prompt as Administrator.
2. Check WinRE status:

reagentc /info

1. Disable WinRE:

reagentc /disable

1. Start DiskPart:

diskpart

1. Select the disk and recovery partition:

list disk
select disk 0
list partition
select partition 4
delete partition override
exit

1. Open Disk Management again.
2. Right-click C:.
3. Choose Extend Volume.
4. Extend into the unallocated space.

After that, re-enable Windows Recovery:

reagentc /enable
reagentc /info

If reagentc /enable fails, tell us the exact error message before doing anything else.

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My recommendation​

Since you appear to have plenty of unallocated space and only a small Recovery partition blocking it, the cleanest approach is:
Use a partition tool to move the 777 MB Recovery partition to the end, then extend C:.
That avoids deleting recovery tools and is usually simpler than rebuilding WinRE manually.
Please also confirm whether BitLocker/device encryption is enabled before you resize anything.