Resolving the TIA Portal V16 WinCC SQL Server Instance Conflict

The error "Please remove the WinCC instance of SQL Server" blocks the TIA Portal V16 (or V15.1) installation or update on a workstation that already hosts TIA Portal V17 or V18 with WinCC Professional or WinCC Unified. The message is generated by the TIA Setup because the bundled Microsoft SQL Server instance expected by the V16 WinCC component collides with a newer SQL Server instance already present on the machine. The fix is not simply "uninstall any SQL Server" — the operator must identify which named SQL instance belongs to the V16 (or older) WinCC component, remove only that instance, and then clean up the orphaned database files before the V16 setup can complete.

This guide consolidates the official Siemens removal workflow with the engineering judgment needed to preserve a working V17/V18 environment.

1. Problem Description

During the install, repair, or update of TIA Portal V16 (or V15.1), the Siemens Setup displays one of the following error dialogs:

• "Please remove the WinCC instance of the SQL Server because it still exists in an incompatible version for TIA Portal STEP 7 & WinCC Professional V15.1 / V16."
• "A SQL Server instance required by WinCC is missing or in an incompatible version."
• "Setup has detected that a previous version of a SQL Server instance used by WinCC Professional is still installed."

The dialog appears immediately after the Setup prerequisites check, before any V16 project components are written to disk. Exit code 0x80004005 is typically written to %TEMP%\Siemens\SetupLogs.

The root cause is a hardcoded dependency between every WinCC Professional / WinCC Runtime Professional / WinCC Unified version and a specific named SQL Server instance with a specific SQL Server build number. When two TIA Portal major versions are installed on the same machine, only one of them can own the SQL instance; the older version's instance is left as an orphan and the newer V16 setup refuses to install over it.

2. Root Cause Analysis

WinCC Professional, WinCC Runtime Professional, and WinCC Unified ship their own private Microsoft SQL Server instance. Each TIA Portal major release pins a specific SQL Server build:

Because all WinCC versions use the same logical instance name WINCC, the Windows Installer for V16 sees a SQL instance at the expected path but with binaries that are too new (V17/V18) or too old (a V15.1 leftover). The Setup's prerequisite check fails with the conflict message because the bundled V16 WinCC setup cannot start the existing WINCC instance to validate the schema version of CC_PM_Starter, CC_PM_Connectivity, and the alarm logging tables.

The official Siemens position is documented in the TIA Portal Updates Readme under Removing an SQL instance (see references in the procedure below): the V16 (or older) WinCC product must be uninstalled through Control Panel, and any orphan SQL instance that survives the WinCC uninstall must be removed separately through Programs and Features.

3. Affected Versions and Compatibility Matrix

The following TIA Portal versions are known to produce the error:

4. Pre-Uninstall Inventory: Identify Which SQL Instance Belongs to V16

Before touching anything, capture a complete picture of the SQL landscape on the workstation. Open Command Prompt (Admin) and run:

sc query | findstr /i "MSSQL"
sc qc "MSSQL$WINCC" | findstr BINARY_PATH_NAME
sc qc "MSSQL$WINCC" | findstr SERVICE_START_NAME

Then enumerate the installed SQL Server instances with their build numbers:

reg query "HKLM\SOFTWARE\Microsoft\Microsoft SQL Server" /s | findstr "CurrentVersion"
reg query "HKLM\SOFTWARE\Microsoft\Microsoft SQL Server\Instance Names\SQL" /s

Cross-reference the build numbers with the table in Section 2. A V16 WinCC installation will report SQL Server 2016 SP2 (13.0.5026.x). If the build number reads 15.0.x, the WINCC instance belongs to V17/V18 and must be preserved.

Confirm the owning TIA Portal version through the Windows registry:

reg query "HKLM\SOFTWARE\Siemens\Automation\InstalledSoftware\TIA" /s | findstr "Version"

Take a screenshot of the following for the change log:

1. appwiz.cpl → list of installed programs (full screen capture).
2. SQL Server Configuration Manager → SQL Server Services (instance state, start type, log-on account).
3. Path of C:\Program Files\Microsoft SQL Server\ showing all installed instance folders.

5. SQL Server Instance Architecture Inside TIA Portal

Every WinCC Professional / Unified installation drops a per-instance folder under %ProgramFiles%\Microsoft SQL Server\:

C:\Program Files\Microsoft SQL Server\
  ├─ MSSQL13.WINCC          (V15.1 / V16 — SQL 2016)
  ├─ MSSQL15.WINCC          (V17 / V18 — SQL 2019)
  └─ MSSQL16.WINCC          (V19 — SQL 2022)

The instance name WINCC is hard-coded in the WinCC services:

WinCC Server (instance=WINCC)
WinCC Archive Server
WinCC Connectivity Server
CCAgent
CCEServer
CcAlgRtServer
CcMsgRtServer

When V16 Setup detects that the path MSSQL13.WINCC\MSSQL\DATA\master.mdf is missing or that the existing MSSQL15.WINCC master database has a newer schema version than V16 expects, the prerequisite check fails and the user sees the remove-the-instance prompt. The newer instance cannot simply be downgraded, so the operator must remove the old instance (or the orphan), then let V16 recreate its own.

6. Step-by-Step Removal Procedure

Follow this exact sequence. Do not skip steps.

6.1 Stop all WinCC and SQL Services

net stop "SQL Server (WINCC)"
net stop "SQL Server Agent (WINCC)"
net stop "CCAgent"
net stop "CCEServer"
net stop "WinCC Server"
taskkill /F /IM sqlservr.exe
taskkill /F /IM sqlwriter.exe

6.2 Uninstall the V16 (or older) WinCC product via Control Panel

1. Press Win + R, type appwiz.cpl, press Enter.
2. Sort by Publisher, locate Siemens AG.
3. Select the V16 entry: SIMATIC STEP 7 / WinCC Professional V16.0 (or V15.1).
4. Click Uninstall / Change and choose Uninstall.
5. Wait for the WinCC uninstall to complete; the SQL instance created by V16 is supposed to be removed automatically.

6.3 Remove the orphan SQL Server instance

If the V16 WinCC uninstall reports success but the WINCC instance is still present (the most common cause of the recurring error), remove the SQL Server entry manually. This is the official Siemens workflow documented in the TIA Portal V20 readme at Removing an SQL instance - TIA Portal V20 Updates and in Removing an SQL instance - TIA Portal V20 Installation:

1. Open the Control Panel.
2. Click Uninstall a program (or Programs and Features).
3. From the list of installed programs, locate the Microsoft SQL Server entry that matches the V16 build (SQL Server 2016, version 13.0.x). The entry typically reads Microsoft SQL Server 2016 (64-bit) with a sub-entry for the WINCC instance.
4. Click Uninstall/Change. The SQL Server Installation Center launches.
5. Select Removal → choose the WINCC instance → click Next.
6. Select SQL Server Database Engine Services, SQL Server Replication, and Client Tools Connectivity for the WINCC instance.
7. Click Next → Remove. The instance binaries are uninstalled; the MSSQL13.WINCC folder is removed automatically.
8. Repeat for the corresponding Microsoft SQL Server 2016 Setup (English) support files if they remain.

6.4 Remove orphan databases and registry keys

Some legacy databases (V15.1 era) survive the SQL uninstall. Clean them up:

del /S /Q "C:\Program Files\Microsoft SQL Server\MSSQL13.WINCC\MSSQL\DATA\*.mdf"
del /S /Q "C:\Program Files\Microsoft SQL Server\MSSQL13.WINCC\MSSQL\DATA\*.ldf"
rmdir /S /Q "C:\Program Files\Microsoft SQL Server\MSSQL13.WINCC"

Remove the registry keys for the dead instance (only if no other product references them):

reg delete "HKLM\SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL13.WINCC" /f
reg delete "HKLM\SOFTWARE\Microsoft\Microsoft SQL Server\Instance Names\SQL\WINCC" /f
reg delete "HKLM\SOFTWARE\Wow6432Node\Microsoft\Microsoft SQL Server\MSSQL13.WINCC" /f

6.5 Clear the WinCC-specific folders

Delete leftover project and archive folders from V15.1/V16 WinCC installations:

rmdir /S /Q "C:\ProgramData\Siemens\Automation\WinCCProjectManagerV16"
rmdir /S /Q "C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Siemens Automation\TIA Portal V16"
rmdir /S /Q "C:\Users\<USER>\AppData\Local\Siemens\TIA Portal V16"

6.6 Reboot

Reboot the workstation. This releases any handle on master.mdf, the registry hive HKLM\SOFTWARE\Microsoft\Microsoft SQL Server, and the WinCC services that survived the previous step.

7. Preserving TIA Portal V17 and V18

The V17/V18 environment uses the MSSQL15.WINCC folder and the SQL Server 2019 binary tree. The removal steps above only touch the MSSQL13.WINCC path, the registry keys under MSSQL13.WINCC, and the V16-specific program entries. To verify that V17/V18 are intact after the cleanup:

1. Open TIA Portal V17 → create a new WinCC Professional project → add a screen with one I/O field → close.
2. Open TIA Portal V18 → compile the same project → verify zero errors.
3. Run sc query "MSSQL$WINCC" → status must read RUNNING.
4. Run sqlcmd -S .\WINCC -E -Q "SELECT @@VERSION" → must return Microsoft SQL Server 2019 (RTM) ....

If the V17/V18 environment no longer starts, the wrong instance was removed. Restore the registry hive from the pre-uninstall export and reinstall the matching SQL Server 2019 instance from the V17 setup media.

8. Reinstall TIA Portal V16

With the SQL landscape clean, launch the V16 Setup:

1. Mount the V16 installation media (DVD ISO or download package).
2. Right-click Start.exe → Run as administrator.
3. Accept the license agreement and choose the destination language.
4. In the product selection, enable WinCC Professional only if the operator actually needs V16 WinCC; otherwise pick STEP 7 Professional alone to avoid re-pulling the SQL instance.
5. Click Install. Setup detects the existing WINCC instance (now SQL 2019 from V17/V18) and registers the V16 WinCC components against the newer instance where the schema permits — or installs a fresh MSSQL13.WINCC if the operator uninstalled the newer one.

Exit codes: 0 = success, 3010 = success with reboot required, anything else = review %TEMP%\Siemens\SetupLogs\Siemens.Setup.Log.

9. Verification Checklist

10. Troubleshooting Matrix

11. Field-Proven Caveats

• Do not run the V16 setup twice in a row. The first run writes partial registry entries under HKLM\SOFTWARE\Siemens\Automation\InstalledSoftware\TIA\V16; the second run collides with them and re-emits the same SQL error.
• Domain service accounts: If the SQL Server WINCC service is running as a domain user, deleting the instance without resetting the SPN can leave stale Kerberos tickets. Re-register the SPN with setspn -R <HOSTNAME>.
• Antivirus interference: Some endpoint protection suites (CrowdStrike, SentinelOne) flag sqlservr.exe during uninstall. Pre-stage the SQL removal in an AV exclusion window.
• Multi-user workstations: Always notify other engineers on the same machine before uninstalling a SQL instance. A second TIA Portal user will lose the live connection to WinCC Runtime.
• VM-based engineering pools: If the engineering station is a Citrix published app or a Windows Server RDS session, the V16 SQL instance is shared across all users. Uninstallation affects the entire pool.