> For the complete documentation index, see [llms.txt](https://docs.up-network.ch/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.up-network.ch/documentation/en/guides/reinstalling-the-operating-system.md).

# Reinstall the operating system

Reinstallation resets the VPS system disk to the state of the chosen image. It erases the data affected by the operation. Back up and export anything you need to keep before confirming.

## VPS with VMmanager

1. Open [VMmanager](https://vps.upnt.ch/) or the management access provided for the service.
2. Select the VPS, checking its name and addresses.
3. Open the operating system reinstallation action.
4. Choose a currently available image and configure the available access options, including your SSH key if the image supports it.
5. Review the scope of deletion, affected disks and settings.
6. Confirm, then wait for the operation to finish. Check its status before starting another action.
7. Verify the connection, IPv4/IPv6 addresses and firewall, then restore your applications.

Reinstallation may change the SSH host keys. Verify the change through the console or service details before replacing the old saved fingerprint.

## Other services

A **physical dedicated server is not reinstalled in VMmanager**. The options depend on the hardware, remote console and delivered service. Ask support for the corresponding process.

For a VDS, use the management method and access details specific to your plan. With Managed, arrange the intervention with the team: you do not have root access to reinstall the managed operating system yourself.

A custom ISO and an automated image are not equivalent. Windows, BSD or virtual router systems may require specific steps and licences. See the [RouterOS CHR guide](/documentation/en/guides/routeros-chr-reinstallation.md) for that case.

If an image or action is missing, open a [ticket](/documentation/en/guides/how-to-open-a-support-ticket.md) with the service and desired operating system.

Updated on 3 October 2026. Reference: [VMmanager operations](https://www.ispsystem.com/docs/v6/virtual-machines/operations-over-virtual-machines).