Resolving WinCC V6.0 SP4 License Compatibility with SP3 Systems

Engineers deploying SIMATIC WinCC V6.0 SP4 Runtime onto a project still running V6.0 SP3 frequently encounter a fatal license error: the new license key on the supplied diskette or USB medium is rejected by the older runtime. This article documents the root cause, the underlying license-architecture change between the two service packs, and the supported resolution path. It also covers pre-upgrade compatibility checks for the surrounding SIMATIC stack (STEP 7, SIMATIC NET, Microsoft SQL Server) and provides a step-by-step migration procedure with verification steps.

1. Problem Statement

A SIMATIC WinCC V6.0 system originally commissioned on Service Pack 3 (SP3) receives a new WinCC Runtime license on diskette, USB dongle, or as a CoL (Certificate of License) download. The package is labeled "WinCC 6.0 SP4 Runtime PowerTags 128" and the license media bears the marking "WinCC/RT 128 v6.0 SP3/SP4". When the engineer attempts to start the WinCC Runtime on the SP3 installation, the following symptoms occur:

• WinCC Explorer opens, but the project does not transition to Runtime.
• The status line reports License Error 104 or License Error 101 (license not found / wrong version).
• AuthorsW (the legacy licensing tool bundled with SP3) does not display the new SP4 license at all.
• Automation License Management (ALM), the SP4-era tool, is not installed on the SP3 host, so the key cannot be imported.
• Downgrading the SP4 key back to a SP3-style authorization is technically impossible - the license container formats are not interchangeable.

Because Siemens no longer sells SP3 authorizations, the engineer cannot simply purchase a replacement. The unsupported workaround would be to run WinCC in demo mode (10-minute Runtime) which is not viable for a production HMI/SCADA system.

2. Why the SP4 License Will Not Activate on SP3

WinCC V6.0 SP4 and V6.0 SP3 use two completely different license-management subsystems. The container that stores a "license" in SP4 has no representation in SP3, and the legacy container that SP3 expects has been retired in SP4. The systems are not interchangeable in either direction except for the documented forward path SP3 → SP4.

2.1 AuthorsW (SP3 and earlier)

Through WinCC V5.x and V6.0 SP3, every WinCC license was an authorization stored in the Windows registry under HKEY_LOCAL_MACHINE\SOFTWARE\SIEMENS\AUTSW\WCCF\... and managed by the AuthorsW.exe utility. Authorizations are tied to a host fingerprint (legacy disk-serial algorithm) and exported/imported via floppy diskette. The container format is proprietary to AuthorsW and predates 2003.

2.2 Automation License Management (SP4 and later)

From V6.0 SP4 onwards, Siemens introduced the license key concept managed by Automation License Management (ALM). License keys were rolled out across the SIMATIC product line in 2003 to replace AuthorsW authorizations. Each key is a signed XML file (.zip container with a LicenseKey.bin payload) bound to the destination host's License Key Server service. ALM exposes a Common Installer API and supports local license servers, network license servers, and USB dongle storage. AuthorsW can no longer read these containers, and SP3 hosts do not ship ALM.

3. Affected Software Versions and Components

Both WinCC server, WinCC client, and WinCC stand-alone stations are affected - the runtime itself gates on the same license service regardless of project topology. Redundant WinCC server pairs require one ALM license per server (no floating licensing on V6.x).

4. WinCC V6.0 SP4 License Specifications

WinCC V6.0 SP4 Runtime licenses are sized by PowerTag count. PowerTags are the externally addressable process tags used in the WinCC Tag Management - internal tags are not counted toward the limit. The legacy "128" license mentioned in the field case is one of the smallest tier. Common SP4 PowerTag tiers and their typical catalog numbers are summarized below.

Additional V6.0 SP4 license options that may have been sold on the same medium must be migrated independently:

• WinCC/Server - enables multi-client access to a WinCC server project.
• WinCC/Redundancy - hot-standby WinCC server pair.
• WinCC/User Archive - enabled by base license, additional counts tier separately.
• WinCC/IndustrialDataBridge - for OPC / database bridging.
• WinCC/Calendar Scheduler / Time Scheduler - time-driven events.
• WinCC/AlarmLogging, WinCC/TagLogging, WinCC/ReportDesigner - included with base Runtime license.

5. Supported Resolution Path

The only supported resolution is to upgrade the WinCC installation from V6.0 SP3 to V6.0 SP4 and install the SP4 license into the new ALM. The upgrade from V6.0 SP3 to V6.0 SP4 is delivered by Siemens as a free service-pack update; you do not need to purchase new software, only the SP4 installation media (CD or downloaded image). The license you have already purchased is forward-compatible to SP4.

The reverse (running an SP4 license against an SP3 host) is not supported, and downgrading the license is not technically possible because the ALM container cannot be unwound into an AuthorsW authorization. Even if a way existed to manipulate the container, the SP3 host lacks the ALM runtime service required to validate the key.

If for documented business reasons the upgrade is not feasible (for example, the host PC is frozen on Windows XP SP2 with a SIMATIC NET version that has not been certified against SP4), the only legal alternative is to escalate to the Siemens regional sales organization or the Siemens Hotline in your country and request a discretionary exception. Siemens historically honors downgrades on a case-by-case basis when the SP3 hardware is end-of-life and a software upgrade is genuinely impossible.

6. Pre-Upgrade Compatibility Checklist

Before installing WinCC V6.0 SP4 over an existing V6.0 SP3 installation, validate that every adjacent component on the PC is compatible. SP4 changes the SQL Server dependency and the SIMATIC NET COM interface; down-rev versions of either can break the upgrade.

6.1 Microsoft SQL Server

WinCC V6.0 SP3 ships and is certified against Microsoft SQL Server 2000 SP3a. SP4 raised the floor to SQL Server 2000 SP4 (or SQL Server 2005 in some configurations) and switched to a different authentication handshake. If your SP3 host is running SQL Server 2000 SP3 or earlier, you must upgrade the SQL Server instance before installing SP4. Verify the installed version with:

Expected response includes 8.00.2039 (SP4) or higher for SQL Server 2000. If the build is below 8.00.760 (SP3a) or 8.00.534 (SP3), apply SQL Server service packs first.

6.2 SIMATIC NET

SIMATIC NET V6.x is required on the PC to access S7 PLCs. WinCC V6.0 SP4 certifies SIMATIC NET V6.4 (or later V6.x). Older SIMATIC NET V6.2 PC software installs have been known to produce S7DOS / S7ONLINE errors after the WinCC upgrade. If you are running SIMATIC NET V6.3 or earlier, plan to upgrade SIMATIC NET alongside WinCC.

6.3 STEP 7

STEP 7 is not strictly required on the WinCC host, but if the same PC is used for both PLC programming and HMI operation (common on commissioning rigs), the STEP 7 version must be compatible with the new WinCC symbol export. STEP 7 V5.3 SP3 is the recommended pairing; earlier V5.2 may produce a Symbol Import Error 0x80004005 on dynamic wizard import.

6.4 Operating System

WinCC V6.0 SP4 retains Windows XP Professional SP2 and Windows 2000 Server SP4 support. Windows NT 4 (the original AuthorsW target) is no longer supported. If your SP3 host is on Windows NT 4 Workstation, a hardware migration is required in addition to the WinCC upgrade.

7. Step-by-Step Migration Procedure

1. Document the existing SP3 project. Export the WinCC project database ("File → Export Project") and back up the entire \<Project>\ directory plus the WinCC archive directory. Record the PowerTag count, options installed, and the AuthorsW authorization IDs.
2. Snapshot the host. Use a disk-imaging tool (Symantec Ghost, Acronis True Image) to capture the SP3 state. If the SP4 install is unsuccessful, restore from this image.
3. Run the SP4 setup. Insert the WinCC V6.0 SP4 CD or mount the ISO. Run Setup.exe and select "Install / Update WinCC". The installer detects the existing V6.0 SP3 and upgrades in place; the existing project databases are preserved.
4. Upgrade SQL Server first if prompted. If WinCC Setup detects a down-level SQL Server, it aborts and asks you to apply SQL Server 2000 SP4 or higher. Install SQL Server service packs, reboot, then re-run WinCC Setup.
5. Reboot and confirm WinCC Explorer opens. Verify the project loads, Runtime can be started in demo mode (yellow status bar), and no DLL version conflicts appear in \<Project>\Diagnostics\DiagLog.txt.
6. Install Automation License Management. If ALM was not installed by the WinCC SP4 setup, install it separately from the WinCC CD under \Automation License Manager\. Confirm the almservice service is set to Automatic in services.msc.
7. Import the SP4 license key. In ALM, choose "Edit → Connect to Target System → Local Host", then "License Key → Install". Browse to the .zip or .alk file on the diskette / USB. ALM writes the key to %ProgramData%\Siemens\Automation\Licenses\ and registers it with the service.
8. Verify license activation. In ALM right-click the license and select "Check". The status icon turns green. If it remains red, confirm the host's Hardware ID matches the CoL that was bound at order time. Re-hosting requires a re-CoL from Siemens and is not free.
9. Start Runtime and confirm tag count. Open WinCC Explorer, start Runtime, and observe the license badge in the status bar. The Runtime shows "Runtime OK" plus the active PowerTag ceiling. If the project exceeds the licensed tag count, Runtime starts in restricted mode and logs License Error 105 to the WinCC diagnostic viewer.
10. Re-archive the migrated project. Export the upgraded project database and back up the new ALM license key to a safe repository. Destroy the old AuthorsW authorizations on the diskette so they are not accidentally restored.

8. Verification

After the migration, perform the following verification matrix. Each row must pass before declaring the system production-ready.

9. Troubleshooting Matrix

10. Operational and Long-Term Considerations

WinCC V6.0 SP4 reached its end-of-life phase in the late 2000s and is no longer supported on current Windows operating systems (Windows 7 and later). When planning the migration off SP3/SP4, consider that the upgrade to SP4 is only a bridge - subsequent Siemens HMI/SCADA platforms (WinCC V7.x, WinCC Professional / TIA Portal, WinCC Unified) provide a much longer support horizon. If the engineering budget allows, capture the upgraded SP4 system's process graphics, archive database, and tag list for later re-implementation on a current platform rather than treating SP4 as the final destination.

Document the ALM license file path, the host Hardware ID, the CoL serial number, and the PowerTag tier in the plant asset register. These five data points allow any successor engineer to recover or re-host the license without contacting Siemens support. Store the original AuthorsW diskette in a sealed ESD bag as an archive - it cannot be re-activated on a SP3 host you no longer have, but it documents the legacy license entitlement.

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