Why can't I expand my C: drive on Windows Server

You used a stock image of Windows Server 2022 Standard Edition or Windows Server 2025 Standard Edition to create your virtual server. You also chose to expand the boot volume up to 250 GB. However, the C: drive cannot be extended.

Because the stock windows image supports both BIOS and UEFI boot, when the boot volume is created, it has a C: drive and a Recovery partition that prevents the expansion of the C: drive.

You can remove the D: drive before you expand the C: drive. Take a snapshot of your boot volume as a precaution before you begin.

Open the Command Prompt or PowerShell as an administrator, and run the following commands:

Disable the Windows Recovery Environment, so the WinRE entry is removed from the Boot Configuration Data and the WinRE image is detached.
```
reagentc /disable
```
```
PS: C:\Users\Administrator> reagentc /disable
REAGENTC.EXE: Operation Successful.
```

Start the DiskPart utility.

diskpart

PS: C:\Users\Administrator> diskpart

Microsoft DiskPart version 10.0.26100.1150

Select the boot disk and list the partitions.

sel disk 1

list part

DISKPART> sel disk 1

Disk 1 is now the selected disk.

DISKPART> list part

  Partition ###  Type          Size    Offset
  -------------  ------------  ------  -------
  Partition 1    Primary       100 MB  1024 KB
  Partition 2    Primary        98 GB   101 MB
  Partition 3    Primary       200 MB    98 GB
  Partition 4    Recovery      681 MB    99 GB

Identify for the partition with the type "recovery", and select it and delete it.

sel part 4

del part override

DISKPART> sel part 4

Partition 4 is now the selected partition.

DISKPART> del part override

DiskPart Successfully deleted the selected partition

DISKPART> list part

  Partition ###  Type          Size    Offset
  -------------  ------------  ------  -------
  Partition 1    Primary       100 MB  1024 KB
  Partition 2    Primary        98 GB   101 MB
  Partition 3    Primary       200 MB    98 GB

Delete the next partition.

DISKPART> sel part 3

Partition 3 is now the selected partition.

DISKPART> del part override

DiskPart Successfully deleted the selected partition

DISKPART> list part

  Partition ###  Type          Size    Offset
  -------------  ------------  ------  -------
  Partition 1    Primary       100 MB  1024 KB
  Partition 2    Primary        98 GB   101 MB

List the disks.

DISKPART> list disk

  Disk ###  Status        Size    Free     Dyn  Gpt
  --------  ------------  ------  -------  ---  ---
  Disk 0    Online         44 KB    44 KB
* Disk 1    Online        100 GB  1087 MB
  Disk 2    Online        378 KB   378 KB

Select the second partition and extend it.

DISKPART> sel part 2

Partition 2 is now the selected partition.

DISKPART> extend

DiskPart successfully extended the volume.

Now you can exit the DiskPart utility by typing the following command.
```
exit
```

Re-enable the Windows Recovery Environment.

PS: C:\Users\Administrator> reagentc /ensable
REAGENTC.EXE: Operation Successful.