# Extend drive C: or add a new disk on Windows Server

> Use new disk space on Windows Server: extend C: with Disk Management or PowerShell, remove a recovery partition that blocks Extend Volume, or add a new disk.

Difficulty: Intermediate

More disk space on a Windows VPS or VDS arrives as raw storage: either as **unallocated space** at the end of the existing disk, or as a **new disk**. Windows does not add it to drive C: on its own. This guide covers both cases on Windows Server 2016 to 2025, including the recovery partition that often blocks **Extend Volume**.

## Before you start

- **Order the space**: open the server under **Services › My Services**, then **Actions › Upgrade/Downgrade Options** for extra disk space or **Upgrade/Downgrade** for a bigger plan; see [upgrade or downgrade a service](/guides/upgrade-or-downgrade-service).
- **Take a snapshot or a backup.** Windows VPS plans include free snapshots; take one before you change partitions.
- Sign in over Remote Desktop with an administrator account; see [first steps on a Windows server](/guides/windows-server-first-steps-rdp).

![The Upgrade/Downgrade Options page with Additional Disks Space next to Additional IPv4 Addresses and Snapshots](https://hyperdc.com/templates/hyperdc/img/docs/upgrade-or-downgrade-service/options.en.webp "Extra disk space is a configurable option of the server. Option names depend on your plan.")

## Step 1: See where the new space is

Open an elevated PowerShell (right-click **Start**, then **Terminal (Admin)** or **Windows PowerShell (Admin)**) and list the disks and partitions:

```powershell
Get-Disk
Get-Partition -DiskNumber 0
```

Or open **Disk Management** (`diskmgmt.msc`) and choose **Action › Rescan Disks**. You will see one of three layouts:

- **Unallocated space directly to the right of C:** follow Case A.
- **A recovery partition between C: and the unallocated space:** follow Case B.
- **A new disk** marked *Not Initialized* or *Offline*: follow Case C.

## Case A: extend C: into the space next to it

In Disk Management, right-click **C:**, choose **Extend Volume**, keep **Maximum available** and finish the wizard. Or in PowerShell:

```powershell
$size = Get-PartitionSupportedSize -DriveLetter C
Resize-Partition -DriveLetter C -Size $size.SizeMax
```

**Verify:** `Get-Volume -DriveLetter C` shows the new size, and File Explorer lists the larger C:.

## Case B: a recovery partition blocks Extend Volume

Windows can only extend a volume into unallocated space **immediately** after it. A small recovery partition behind C: stops that. The fix moves Windows RE onto C:, removes the partition and then extends C:.

> **Warning**
>
> This changes the partition table. Take a snapshot or backup first, and select partitions by the numbers **your** `list part` output shows.

1. In an elevated Command Prompt or PowerShell, check and disable Windows RE. When it is disabled, its image is kept in `C:\Windows\System32\Recovery`:

```text
reagentc /info
reagentc /disable
```

2. Start `diskpart`, find the recovery partition and delete it:

```text
diskpart
list disk
select disk 0
list part
select part 4
delete partition override
exit
```

Replace `4` with the number of the partition of type **Recovery** that sits after C: in your `list part` output.

3. Extend C: as in Case A.

4. Enable Windows RE again. Without a recovery partition, it uses the image on C:

```text
reagentc /enable
reagentc /info
```

**Verify:** `reagentc /info` shows **Windows RE status: Enabled**, and C: has the new size.

## Case C: bring a new disk online

A new disk is empty and may be offline. Find its number (here `1`), bring it online if needed, initialise it with GPT, create one partition and format it with NTFS:

```powershell
Get-Disk
Set-Disk -Number 1 -IsOffline $false
Initialize-Disk -Number 1 -PartitionStyle GPT
New-Partition -DiskNumber 1 -UseMaximumSize -AssignDriveLetter | Format-Volume -FileSystem NTFS -NewFileSystemLabel "Data"
```

Skip `Set-Disk` if the disk is already online. In Disk Management the same steps are: right-click the disk, **Online**, **Initialize Disk** (GPT), then right-click the unallocated space and **New Simple Volume**.

**Verify:** `Get-Volume` lists the new drive letter with the label **Data**, and you can create a folder on it.

## Troubleshooting

**`Get-PartitionSupportedSize` shows the same maximum as the current size.** The unallocated space is not directly after C: (see Case B), or Windows has not seen the new size yet: run **Rescan Disks** in Disk Management.

**`delete partition` stops with "Cannot delete a protected partition without the force protected parameter set".** That is expected for a recovery partition, which is why the command above adds `override`. Never use `override` on any other partition: the EFI system partition and C: itself are needed to boot.

**`reagentc /enable` reports an error.** Check that `C:\Windows\System32\Recovery\Winre.wim` exists. If it does not, Windows RE cannot be enabled from C:; the server still runs normally, and you can restore from your snapshot if you need Windows RE.

**The new disk does not appear at all.** Choose **Action › Rescan Disks**; if it is still missing, open a ticket with the output of `Get-Disk`.

## Next steps

- Keep Windows up to date after the change: [fix Windows Update problems](/guides/fix-windows-update-problems).
- Linux servers: [use new disk space on a Linux server](/guides/use-new-disk-space-linux).

## Frequently asked questions

### Why is Extend Volume greyed out?

Windows can only extend a volume into unallocated space directly to its right on the same disk. On many images a small recovery partition sits between C: and the new space; this guide shows how to deal with it.

### Do I need to restart?

No. Extending NTFS volumes and bringing new disks online works while Windows runs. If Disk Management does not show the new space, choose Action › Rescan Disks first.

### Is it safe to delete the recovery partition?

It holds Windows RE, the recovery environment. When you disable Windows RE first, Windows copies its image to the system drive, and enabling it again afterwards keeps recovery working from C:. Take a snapshot or backup before you change partitions.

### Can I shrink C: again later?

Shrinking a volume is possible inside Windows, but the server's disk itself cannot be made smaller. Moving to a plan with a smaller disk means backing up, ordering the smaller plan and restoring.

---

Source: <https://hyperdc.com/guides/products/extend-windows-disk>\
Updated: 2026-10-15