# Migration of Orthanc 1.5.3 from Windows Server 2016 to Windows Server 2025
**URL:** https://discourse.orthanc-server.org/t/migration-of-orthanc-1-5-3-from-windows-server-2016-to-windows-server-2025/6433
**Category:** General
**Created:** [April 24, 2026, 7:18am UTC](https://discourse.orthanc-server.org/t/migration-of-orthanc-1-5-3-from-windows-server-2016-to-windows-server-2025/6433 "2026-04-24T07:18:49Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@Tecnico20\_MelaC](https://discourse.orthanc-server.org/u/Tecnico20_MelaC)
#### Post date: [April 24, 2026, 7:18am UTC](https://discourse.orthanc-server.org/t/migration-of-orthanc-1-5-3-from-windows-server-2016-to-windows-server-2025/6433/1 "2026-04-24T07:18:49Z")
Hello,
I need to migrate an existing Orthanc installation to a new server and I would like to confirm the best approach before proceeding.
**Current setup:**
- Orthanc 1.5.3 on Windows Server 2016 (VM on VMware ESXi)
- Storage backend: filesystem (no PostgreSQL/MySQL plugin active)
- Index: SQLite (default) β confirmed via `/system` endpoint: `DatabaseBackendPlugin: null`, `StorageAreaPlugin: null`
- Storage path: `D:\Archivio` (~2TB of DICOM files)
- Loaded plugins: OrthancWebViewer, OsimisWebViewer, OrthancDicomWeb, OrthancWSI, ServeFolders, ModalityWorklists, MySQL (index+storage), PostgreSQL (index+storage) β however MySQL and PostgreSQL are loaded but not active as backends
- No HTTP authentication enabled
**Target setup:**
- New Windows Server 2025 VM (Proxmox)
- Same Orthanc version (1.5.3) to keep compatibility
- Same folder structure (`D:\Archivio`)
- Same IP address as the old server (to avoid reconfiguring DICOM modalities)
**Planned migration steps:**
1. Stop Orthanc on the old server
2. Copy the entire `D:\Archivio` folder to the new server using Robocopy (including the SQLite index file)
3. Copy `orthanc.json` and all plugin configuration files
4. Copy all plugin `.dll` files
5. Start Orthanc on the new server
**Questions:**
1. Is copying the SQLite index file (`.db`) along with the DICOM files sufficient, or should we rebuild the index from scratch on the new server?
2. Are there any known compatibility issues running Orthanc 1.5.3 plugins (compiled for Windows) on Windows Server 2025?
3. Would you recommend upgrading directly to the latest Orthanc version during migration, or is it safer to migrate first with 1.5.3 and upgrade later?
4. The current installation runs Orthanc 1.5.3, but the Windows installer archive uses a date-based versioning scheme (YY.MM.x). Which installer version corresponds to Orthanc 1.5.3, or would you recommend migrating directly to the latest version (26.4.1) instead of trying to match the exact version?
Thank you in advance.
---
### Author:  [@alainmazy](https://discourse.orthanc-server.org/u/alainmazy)
#### Post date: [April 28, 2026, 7:14am UTC](https://discourse.orthanc-server.org/t/migration-of-orthanc-1-5-3-from-windows-server-2016-to-windows-server-2025/6433/2 "2026-04-28T07:14:35Z")
Hi
Your proposed upgrade plan is correct.
> [@Tecnico20\_MelaC](#):
>
> Is copying the SQLite index file (`.db`) along with the DICOM files sufficient, or should we rebuild the index from scratch on the new server?
Copying the SQLite index is enough (note there might be one or 2 extra files like `index-wal`)
> [@Tecnico20\_MelaC](#):
>
> Are there any known compatibility issues running Orthanc 1.5.3 plugins (compiled for Windows) on Windows Server 2025?
No
> [@Tecnico20\_MelaC](#):
>
> Would you recommend upgrading directly to the latest Orthanc version during migration, or is it safer to migrate first with 1.5.3 and upgrade later?
It should be equivalent (and, you have a backup right ?)
> [@Tecnico20\_MelaC](#):
>
> The current installation runs Orthanc 1.5.3, but the Windows installer archive uses a date-based versioning scheme (YY.MM.x). Which installer version corresponds to Orthanc 1.5.3, or would you recommend migrating directly to the latest version (26.4.1) instead of trying to match the exact version?
[Version 19.1.1 (7 years ago !)](https://github.com/orthanc-server/orthanc-builder/blob/f7be69975360d3a61977547e4d1de4668fbc8fe6/release-notes-docker-images.md?plain=1#L945)
Hope this helps,
Alain.
---
### Author:  [@Tecnico20\_MelaC](https://discourse.orthanc-server.org/u/Tecnico20_MelaC)
#### Post date: [April 28, 2026, 10:42am UTC](https://discourse.orthanc-server.org/t/migration-of-orthanc-1-5-3-from-windows-server-2016-to-windows-server-2025/6433/3 "2026-04-28T10:42:04Z")
Hello Alain,
thank you for your previous answer.
One more question regarding the upgrade: would you recommend installing Orthanc 1.5.3 (installer 19.1.1) on the new server first, migrating the data, verifying everything works, and then upgrading to the latest version (26.4.1)? Or is it better to install 26.4.1 directly and migrate in one shot?
Yes, we have a backup, but i hope i donβt need it π
---
### Author:  [@Tecnico20\_MelaC](https://discourse.orthanc-server.org/u/Tecnico20_MelaC)
#### Post date: [April 28, 2026, 10:50am UTC](https://discourse.orthanc-server.org/t/migration-of-orthanc-1-5-3-from-windows-server-2016-to-windows-server-2025/6433/4 "2026-04-28T10:50:09Z")
Hello Alain,
when migrating to a fresh Orthanc 26.4.1 installation, should we copy the plugin `.dll` files from the old Orthanc 1.5.3 installation, or does the new installer already include them?
Thank you.
---
### Author:  [@alainmazy](https://discourse.orthanc-server.org/u/alainmazy)
#### Post date: [April 29, 2026, 6:59am UTC](https://discourse.orthanc-server.org/t/migration-of-orthanc-1-5-3-from-windows-server-2016-to-windows-server-2025/6433/5 "2026-04-29T06:59:57Z")
> [@Tecnico20\_MelaC](#):
>
> One more question regarding the upgrade: would you recommend installing Orthanc 1.5.3 (installer 19.1.1) on the new server first, migrating the data, verifying everything works, and then upgrading to the latest version (26.4.1)? Or is it better to install 26.4.1 directly and migrate in one shot?
Yes, you can install 26.4.1 directly
---
### Author:  [@alainmazy](https://discourse.orthanc-server.org/u/alainmazy)
#### Post date: [April 29, 2026, 7:00am UTC](https://discourse.orthanc-server.org/t/migration-of-orthanc-1-5-3-from-windows-server-2016-to-windows-server-2025/6433/6 "2026-04-29T07:00:23Z")
> [@Tecnico20\_MelaC](#):
>
> when migrating to a fresh Orthanc 26.4.1 installation, should we copy the plugin `.dll` files from the old Orthanc 1.5.3 installation, or does the new installer already include them?
Of course, the 26.4.1 installer comes with the latest versions of the .dll