Resolving Windows Installer Error 1719 During SIMATIC PCS 7 Installation

Windows Installer Error 1719 ('Windows Installer service could not be accessed. Contact your support personnel to verify that it is properly registered and enabled') during multi-disc or second-phase installation of SIMATIC PCS 7 V8.0 SP2 indicates that the Windows Installer daemon (msiexec.exe / msiserver) is deregistered, disabled in service configuration, or blocked by an unresolved pending reboot lock. In 64-bit Windows environments, this occurs when 32-bit and 64-bit installer binaries become desynchronized. To resolve Error 1719, re-register the Windows Installer service via command prompt (msiexec /unregister followed by msiexec /regserver), set the startup type of Windows Installer to Manual, clear pending rename operations in the registry, and relaunch setup.

Windows Installer Architecture and Multi-Disc PCS 7 Setup

The SIMATIC PCS 7 software suite is distributed across multiple installation media DVDs comprising hundreds of modular Microsoft Installer packages (*.msi). The PCS 7 master installer (Setup.exe) coordinates package deployment by invoking the Windows Installer service (msiserver, executed via msiexec.exe).

When installing Disc 2 (which contains optional engineering tools, libraries, and WinCC add-ons), the setup bootstrapper switches installer contexts. If the Windows Installer service crashes during package transitions, or if the COM service registration in the Windows registry becomes corrupted, subsequent MSI calls fail instantly with Error 1719.

Root Causes: Service Deregistration, WOW64 Redirection, and Reboot Locks

Three technical conditions typically trigger Error 1719 during Siemens software installations:
1. Deregistered Windows Installer Service: Third-party software uninstallers or aggressive registry cleaners frequently damage keys under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\msiserver. The service fails to respond to DCOM activation requests from Setup.exe.
2. 64-Bit WOW64 Binary Mismatch: On 64-bit Windows platforms (Windows 7 64-bit, Windows Server 2008 R2), two versions of msiexec.exe exist: the 64-bit binary in System32 and the 32-bit binary in SysWOW64. Both must be registered correctly to allow the Siemens installer to deploy both 32-bit STEP 7 components and 64-bit SQL Server/WinCC drivers.
3. Pending File Rename Operations (Installer Mutex Lock): If a preceding package or Windows Update flagged files for replacement on reboot (PendingFileRenameOperations), Windows Installer blocks new installation threads until the system restarts.

Diagnostic Matrix for Windows Installer Error 1719

The table below details error codes, service states, and corrective actions for Windows Installer faults:

Error Code / IndicatorService StateRoot CauseCorrective Engineering ActionError 1719Stopped / Disabledmsiserver COM registration damaged or service disabled.Re-register msiexec; set Startup type to Manual in services.msc.Error 1618RunningAnother installation is already in progress.Terminate rogue msiexec.exe instances via Task Manager.PendingFileRenameRegistry Key SetWindows reboot lock active in Session Manager.Delete PendingFileRenameOperations value in registry and reboot.msiserver in Safe ModeDisabledWindows operating under Safe Mode policies.Enable Windows Installer under Safe Mode registry keys if required.msiexec /regserverSystem CommandRebinds DLLs and COM interfaces for msiserver.Core resolution command executed in administrative command prompt.

Step-by-Step Procedure to Re-Register and Restore Windows Installer

Terminate Lingering Installer Processes:
- Open Windows Task Manager as Administrator.
- Navigate to the Details or Processes tab: locate all instances of msiexec.exe.
- Click End Process Tree to terminate hanging installer threads.
Re-Register Windows Installer via Command Prompt:
- Open Command Prompt as Administrator (cmd.exe).
- Unregister the installer service by typing: msiexec /unregister and press Enter.
- Re-register the installer service by typing: msiexec /regserver and press Enter.
Re-Register 32-Bit WOW64 Engine (On 64-Bit Windows):
- In the same administrative command prompt, navigate to SysWOW64 and execute registration:
cmd cd %windir%\SysWOW64 msiexec.exe /regserver
Verify Windows Installer Service Configuration:
- Open services.msc -> locate Windows Installer.
- Verify that Startup type is set to Manual (not Disabled).
- Click Start to verify that the service transitions to Running without error 1719.
Clear Pending Reboot Operations:
- Open Registry Editor (regedit.exe).
- Navigate to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager.
- Locate value PendingFileRenameOperations: right-click and select Delete.
Relaunch PCS 7 Setup Disc 2: Reboot the workstation, insert Disc 2, and launch Setup.exe with administrative privileges.

Verification

Verify resolution through the following milestones:
1. Confirm that msiexec.exe launches from the command line without throwing service registration warnings.
2. In the Windows Application Event Log (eventvwr.msc), verify that event MsiInstaller logs successful package starts.
3. Confirm that the PCS 7 Disc 2 setup progress bar advances past the initial component extraction and completes installation cleanly.

Limitations and Operational Precautions

Never set the Windows Installer service startup type to 'Automatic'. Microsoft Windows by design configures Windows Installer for on-demand 'Manual' startup; setting it to Automatic can cause boot delays and race conditions with other startup services. Furthermore, avoid modifying security permissions on the C:\Windows\Installer directory, as tampering with system ACLs prevents Windows Installer from accessing cached patch files.