Operating System Upgrade and Migration Strategy from PCS 7 V9.0 to V9.1

Upgrading SIMATIC PCS 7 from V9.0 to V9.1 requires upgrading the underlying operating systems, because PCS 7 V9.1 strictly mandates Windows 10 Enterprise LTSC 2019 (64-bit) for engineering stations and OS clients, and Windows Server 2019 Standard or Datacenter for OS servers, dropping support for Windows 10 LTSB 2016 and Windows Server 2016. In-place operating system upgrades are strictly prohibited by Siemens because they corrupt SQL Server instances, WinCC message queues, and SIMATIC Shell bindings. The approved procedure requires creating complete project and database backups, performing clean operating system installations using Siemens Restore media, installing PCS 7 V9.1, and executing guided project migration.

Executive Summary

Software lifecycle modernization from SIMATIC PCS 7 V9.0 to V9.1 delivers critical cyber security enhancements, updated controller firmware support, and Microsoft SQL Server 2017 integration. A major hurdle encountered by plant engineering teams is the fundamental operating system baseline shift: PCS 7 V9.1 drops compatibility with Windows 10 LTSB 2016 and Windows Server 2016, mandating Windows 10 Enterprise LTSC 2019 and Windows Server 2019. System administrators frequently consider performing Windows in-place upgrades on production servers to preserve installed software. In industrial automation environments, in-place OS upgrades inevitably compromise database integrity. This article presents the technical justification against in-place upgrades, details OS licensing requirements, and outlines the official clean-install migration roadmap.

Architecture and Fundamental Mechanics

DCS Operating System Dependencies, In-Place Upgrade Failure Modes, and Migration Options:

Operating System Compatibility Discrepancy:
PCS 7 V9.0 (including SP1/SP2/SP3): Runs on Windows 10 Enterprise LTSB 2016 (Build 14393) and Windows Server 2016 Standard.
PCS 7 V9.1 (including SP1/SP2): Exclusively certified on Windows 10 Enterprise LTSC 2019 (Build 17763) and Windows Server 2019 Standard/Datacenter.
Running PCS 7 V9.1 on Windows Server 2016 or LTSB 2016 is blocked by the setup pre-check utility.
The Destructive Nature of In-Place Windows Upgrades:
An in-place Windows upgrade (e.g. inserting a Windows Server 2019 DVD into a running Windows Server 2016 machine and selecting 'Upgrade') leaves legacy registry branches, security identifiers, and driver bindings intact while replacing OS subsystems.
SQL Server Instance Breakdown: WinCC relies on tightly coupled Microsoft SQL Server instances (WINCC). In-place OS upgrades break SQL Server service account permissions and DCOM class registrations, causing WinCC_sys.log database connection crashes.
Message Queuing and Shell Corruption: Microsoft Message Queuing (MSMQ) and SIMATIC Shell drivers fail to re-bind to network interfaces, permanently breaking Terminal Bus station discovery.
Clean Installation via Siemens Restore Media vs Commercial Media:
Siemens provides pre-configured operating system image restore media for SIMATIC Industrial PCs (e.g. IPC647E, IPC847E, IPC547J).
These restore packages contain the validated LTSC operating system, pre-tuned Windows security policies, disabled power throttling, and verified chipset drivers.
If utilizing third-party commercial servers (e.g. Dell PowerEdge or HP ProLiant), perform a clean Windows Server 2019 installation and apply the official Siemens Security Controller settings during PCS 7 setup.

Step-by-Step Implementation Procedure

Secure Baseline Backups on the Existing V9.0 System:
* On the Engineering Station, create a complete project archive in SIMATIC Manager via File > Archive (choose ZIP format).
* On redundant OS Servers, use WinCC Project Duplicator or manual export to back up SQL runtime databases, Alarm Logging archives, and Tag Logging slow/fast archives.
* Back up all installed license keys to a USB transfer drive using Automation License Manager (ALM).
Procure Valid Operating System and PCS 7 V9.1 Upgrade Licenses:
* Confirm acquisition of Windows 10 Enterprise LTSC 2019 and Windows Server 2019 licenses.
* Procure the appropriate PCS 7 V9.0 to V9.1 Software Upgrade Package from an authorized Siemens distributor.
Clean Operating System Deployment:
* Boot target IPCs using the Siemens Restore DVD/USB for Windows 10 Enterprise LTSC 2019 (for clients/ES) or Windows Server 2019 (for servers).
* If using commercial servers, format the primary partition completely; do not preserve previous Windows folders (Windows.old).
* Configure the host name, static IP addresses for Terminal Bus and Plant Bus, and join the plant Active Directory domain.
Install SIMATIC PCS 7 V9.1 Software Stack:
* Launch PCS 7 V9.1 Setup.exe with administrative privileges.
* Install Microsoft .NET Framework 3.5 SP1 (using DISM offline source if internet access is disabled).
* Select the designated package role (Engineering Station, OS Server, or OS Client).
* Allow setup to install Microsoft SQL Server 2017 and execute the Security Controller hardening script.
Migrate Project Database and Download to Stations:
* Retrieve the V9.0 project archive into SIMATIC Manager on the new V9.1 Engineering Station.
* Allow the automatic database conversion wizard to upgrade project schemas to V9.1.
* Open OS Project Editor, update basic system pictures, compile the OS, and perform initial Entire OS downloads.

Verification

Run winver on all stations; verify Windows 10 Enterprise LTSC 2019 (Build 17763) or Windows Server 2019.
Open Windows Services (services.msc); verify that SQL Server (WINCC) and SIMATIC Shell are Running.
Open SIMATIC Shell in Windows File Explorer; verify that all servers, clients, and the ES discover each other across the Terminal Bus.
Start WinCC Runtime; verify that process graphics render seamlessly and alarm archiving operates with zero database errors.

Limitations and Operational Precautions

In-place OS upgrades are entirely unsupported by Siemens Technical Support. If an in-place upgrade is attempted and fails, the only remediation is wiping the hard drives and performing a clean installation. Upgrading project libraries (APL) from V9.0 to V9.1 can be performed with or without utilization of new functions, depending on plant operational requirements.

Engineer FAQ

Can I do an in-place Windows upgrade from Server 2016 to Server 2016 on a PCS 7 server?

No. In-place Windows upgrades break SQL Server instances, DCOM configurations, and WinCC message queues. Clean installations are mandatory.

What operating systems are supported for PCS 7 V9.1?

Windows 10 Enterprise LTSC 2019 (64-bit) for ES/Clients, and Windows Server 2019 Standard/Datacenter for OS Servers.

Do I need to purchase new Windows licenses when upgrading to PCS 7 V9.1?

Yes, upgrading Windows Server 2016 to 2019 or LTSB 2016 to LTSC 2019 requires valid Microsoft OS licenses, procurable via Siemens IPC restore media or volume licensing.