Resolving WinCC 7.3 Autostart Failure After Runtime Shutdown

Problem Summary

On a SIMATIC WinCC 7.3 PC station, the Autostart mechanism appears to operate correctly during the first boot: the configured project loads and Runtime graphics render in the full-screen window. The defect surfaces only after the operator performs the equivalent of a cold shutdown while the project is still active. Two symptoms are reproducibly observed:

1. On the next Shut down of Windows, a warning dialog states that the WinCC project is still open and blocks the shutdown sequence.
2. If the operator selects Force shutdown anyway (the only option the operator ever chooses in production), the subsequent power-on does NOT bring Runtime up again. The PC boots to the Windows desktop and the Autostart entry is silently skipped.

This is observed on the WinCC 7.3 SP3 / Update 3 baseline running on Windows 10 (64-bit), although the same root cause applies to any WinCC 7.3 installation whose Runtime graphics window is closed with the Microsoft-style X button instead of through the WinCC-native shutdown path.

Affected Versions and OS Compatibility

Reference: Siemens KB 97493192 — WinCC 7.3: Which operating systems are supported?. Windows 10 was never added to the supported OS matrix for WinCC 7.3, so any new OS sub-version (1709, 1909, 21H2, etc.) can break features that previously worked, including Autostart.

Root Cause Analysis

The Windows message "WinCC project is still open" during shutdown is raised by the WinCC project service CCProjectMgr.exe (project manager), not by the Runtime process CCRT.exe. When the operator clicks the X button on the Runtime window, only the graphical Runtime instance terminates. The CCProjectMgr background service keeps the project opened in memory and writes state to the registry key:

This flag survives a forced power-cut. On the next boot, the WinCC Autostart hook checks the same registry flag. Because the flag still reads 1, the Autostart logic interprets the situation as "Runtime was already terminated, the project should be re-attached" and silently skips the visible Runtime start. The CS (configuration studio) loads in the background, but no CCRT.exe is spawned — so the operator sees an empty Windows desktop.

Component Lifecycle Affected

Only the bottom row of the table is "cleanly" terminated by the X-button. The rest of the project keeps running headlessly, which both generates the shutdown warning and contaminates the Autostart state.

Solution 1 — Replace the X-Button with StopRuntime

The WinCC system function StopRuntime is the official shutdown channel. It performs the same orchestration as the Autostart stop path (CCRT.exe → CCProjectMgr → CCAlg → CCSyslog → MSSQL), then clears the ProjectActive flag so the next Autostart cycle launches a fresh Runtime.

Implementation in a WinCC Graphics Designer Button

1. Open the WinCC Explorer of the affected project.
2. Open Graphics Designer and select the button used to close Runtime (or add a dedicated "Exit" button on the start picture).
3. In the Event → Mouse → Click configuration dialog, insert a C-Action (or VBScript action) calling the system function.

// C-Action terminating Runtime cleanly
StopRuntime(GetTagChar("@CurrentUser")); // optional parameter: user name logged to CS log

If the project uses VBScript (ANSI-C alternative):

' VBScript on the same Mouse-Click event
Dim objShell
Set objShell = CreateObject("WScript.Shell")
' Built-in HMIRuntime object — preferred path:
HMIRuntime.Stop ' terminates WinCC RT without leaving the headless project running
Set objShell = Nothing

Build the project, deploy it to the Runtime PC, and disable access to the X-button (borderless full-screen mode is already set in the computer properties of the WinCC project; verify Start Picture / Window → Full Screen).

Solution 2 — Configure Autostart Correctly

The Autostart feature is enabled in two places and both must be set or the failure mode in this article will recur. The configuration path follows Siemens KB 23061262 — How do you configure the WinCC Runtime autostart?:

Step A — WinCC Explorer (project-level autostart)

1. In the WinCC Explorer of the project, right-click Computer and select Properties.
2. Open the Startup tab.
3. Tick "Activate project at autostart".
4. Choose the desired Runtime start mode: Start WinCC Runtime and open the start picture.
5. Confirm with OK; the project file McCfgSrvr.ini in the project path is updated.

Step B — Windows Autostart (OS-level trigger)

1. Open the WinCC communication / autostart tool: Start → Siemens Automation → WinCC → "Autostart".
2. Select "Activate Autostart".
3. The tool inserts a registry value WinCC /auto under HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run (or a service configuration equivalent, depending on WinCC version) pointing at CCExplorer.exe -activate:".\".
4. Restart the PC; Runtime must come up unattended.

Solution 3 — Recovery with reset_wincc.vbs

If Runtime has been left in the headless state (X-button was used, project still loaded), force a controlled reset before the next boot:

1. Log on to Windows with the WinCC operator account.
2. Press Win + R, type reset_wincc.vbs, press Enter. The script is shipped under %WinCC_DIR%\bin\reset_wincc.vbs.
3. The VBScript resets the ProjectActive registry flag, closes any residual CCProjectMgr instance, and clears lock files under <ProjectPath>\<ComputerName>\RT\.
4. Reboot the PC.
5. After boot, Autostart brings Runtime up as expected.

What reset_wincc.vbs Performs

' Relevant logic extracted (paraphrased) — official file is editable for diagnostics
Sub StopProject()
  Dim sh : Set sh = CreateObject("WScript.Shell")
  sh.Run Chr(34) & CCInstallDir & "\bin\CCProjectMgr.exe" & Chr(34) & " /close", 0, True
  WScript.Sleep 3000
  sh.RegWrite "HKLM\SOFTWARE\Wow6432Node\Siemens\Automation\WinCC\RT\ProjectActive", 0, "REG_DWORD"
End Sub

Solution 4 — Forced Shutdown Recovery Procedure

When Windows presents the "WinCC project is still open" warning during a planned shutdown:

1. Do NOT select Force shutdown anyway.
2. Click Cancel — Windows cancels the shutdown attempt and brings the WinCC Runtime window back to the foreground.
3. If only a small popup requesting project-close appears, confirm and let the project close itself.
4. Right-click the WinCC icon in the Windows system tray (notification area). If no tray icon is visible because Runtime was launched full-screen with the X-button earlier, skip to step 5.
5. Select "Exit WinCC Explorer" (or use the project-internal StopRuntime button per Solution 1).
6. Confirm that CCProjectMgr.exe disappears from Task Manager.
7. Reissue the Shut down command. The shutdown will no longer be blocked.

Solution 5 — Long-Term Fix: Upgrade to WinCC 7.4+

If the PC must run Windows 10 (and Windows 10 is required in your hardware specification), plan a project migration from WinCC 7.3 to WinCC 7.4 SPx or later. The migration preserves the project structure but allows the WinCC team to certify the Windows 10 build.

1. Inventory the WinCC 7.3 project — note installed options (WinCC/WebNavigator, WinCC/Connectivity Pack, WinCC/Audit, etc.).
2. Order the matching WinCC 7.4 SPx license set with the same option bundle; check the SIMATIC WinCC Catalog (article number 6AV6 383-…) and the corresponding Software Update Service contract.
3. Build a side-by-side engineering station; import the WinCC 7.3 project — the project migration wizard (Start → SIMATIC → WinCC → Project Migrator) automates the conversion.
4. Accept, test, and re-baseline the C-script and VBScript functions; the VBS module API is stable but HMIRuntime namespace receives additions (e.g., Tags, Screens) that may shadow legacy calls.
5. Validate on a Windows 10 21H2 LTSC image before redeployment.

Verification Procedure

1. Reboot the PC and confirm that the configured start picture appears without operator interaction.
2. Validate Runtime is active: Task Manager → More details → CCRT.exe present, CPU > 1%, Working Set > 80 MB.
3. Exit Runtime through the in-project shutdown button only (Solution 1). Confirm the Windows desktop returns within 5 s and no shutdown-warning dialog is raised.
4. Re-issue Shut down — confirm no "WinCC project still open" warning appears and that the PC powers off normally.
5. Power on the PC; confirm Runtime comes up unattended. If it does, the fix is in place.

Troubleshooting Matrix

Related Issue — WinCC Unified Autostart on Windows PC

Projects deployed under WinCC Unified (V16+) on a PC station exhibit a related but distinct failure: after a Windows reboot the Autostart aborts and the following entry appears in the Windows Application log:

Log Name:      Application
Source:        Service Control Manager
Event ID:      7009
Description:   A timeout was reached (30000 milliseconds) while waiting for
               the MSSQL$WinCCUnified service to connect.

The root cause is again a service-start-order race between the SIMATIC Runtime Manager and the instance MSSQL$WinCCUnified. Per Siemens KB 109798589 — Why does the automatic start of a WinCC Unified RT on a Windows PC fail with the message "A timeout was reached (30000 milliseconds) while waiting for the MSSQL$WinCCUnified service to connect" in the Windows event log?, the corrective actions are:

1. Set the WinCCUnifiedRT service to Automatic (Delayed Start).
2. Add an explicit service dependency to MSSQL$WinCCUnified through the registry:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\WinCCUnifiedRT]
"DependOnService"=hex(7):4d,00,53,00,53,00,51,00,4c,00,24,00,57,00,69,00,\
  6e,00,43,00,43,00,55,00,6e,00,69,00,66,00,69,00,65,00,64,00,00,00,00,00

3. Reboot and re-test Autostart.

The same delayed-start pattern also eliminates sporadic Autostart hangs in WinCC 7.x when the WINCC SQL instance is slow to come up after a Windows cumulative update.

Best Practices for Production HMI Stations

• Use Windows 10 Enterprise LTSC 2019 / 2021 on every WinCC Runtime PC; avoid consumer or SAC editions.
• Disable Windows automatic updates; schedule them quarterly after a bench-test.
• Replace every "close" button on WinCC graphics with a StopRuntime action — never rely on the OS-level X-button.
• Disable the system menu (close-box) on the Runtime start picture via the picture's Window Attributes dialog (set "Close button enabled = Off; if this is not available on 7.3, hide the close button through Win32 SetWindowLong(hwnd, GWL_STYLE, GetWindowLong(hwnd, GWL_STYLE) And Not WS_SYSMENU) inside a global C action on picture load).
• Schedule an unattended shutdown test in every FAT (factory acceptance test): exit Runtime via the in-project button, shut down, power-up, confirm Runtime appears without operator interaction.
• Keep reset_wincc.vbs on the operator desktop as a recovery icon, but password-protect its shortcut under a separate engineering account to discourage misuse.

Glossary of WinCC Processes

Frequently Asked Questions