S7-PLCSIM V5.4 Installation Error on Windows 7 Ultimate: Complete Fix Guide

S7-PLCSIM V5.4 is the Siemens off-line simulation runtime for STEP 7 V5.4 / V5.5 projects targeting S7-300 and S7-400 CPUs. Engineers running Windows 7 Ultimate frequently encounter installer failures when the base version (without Service Pack 5) is launched because the original V5.4 release pre-dates Windows 7 RTM and cannot resolve certain OS-specific API calls. This article documents the root cause, the corrective Service Pack, the verification procedure, and edge-case workarounds for the most common installation faults on Windows 7 Ultimate (32-bit and 64-bit).

1. Product Identification and Version Mapping

Before troubleshooting, identify exactly which component the installer is staging. S7-PLCSIM ships as a stand-alone DVD image (order number 6ES7 841-0CC05-0YA5 for V5.4 SP5) and is also embedded in the STEP 7 V5.5 media. The base V5.4 build (released 2006) does not contain the Windows 7-aware installer shell introduced in 2009.

To confirm the currently installed version, navigate to C:\Program Files\Siemens\Automation\PLCSIM\bin (32-bit) or C:\Program Files (x86)\Siemens\Automation\PLCSIM\bin (64-bit) and right-click s7wsimax.dll → Properties → Details. The "File version" and "Product version" fields expose the patch level.

2. Problem Description and Symptom Catalogue

The reported symptom is a non-recoverable installer failure when launching the S7-PLCSIM V5.4 setup.exe on Windows 7 Ultimate SP1 (build 7601). The exact failure mode depends on the elevation context, UAC status, and whether STEP 7 is already present.

2.1 Primary Symptoms

• Setup wizard halts at "Searching for installed components" with a generic error dialog.
• MSI rollback executes silently, leaving partial registry keys under HKLM\SOFTWARE\Siemens\AUTSW\PLCSIM.
• Event Viewer (Application log) records Event ID 10005 from MsiInstaller with description "The system cannot find the file specified" (HRESULT 0x80070002).
• Subsequent setup launches fail with "Another installation is already in progress" because the previous MSI handle is not released.
• On 64-bit Windows 7, the installer may emit "ERROR: Failed to register S7WSIMAX.DLL — module not found" even though the file is physically present.

2.2 Secondary Symptoms

• STEP 7 V5.5 launches successfully but S7-PLCSIM menu item is greyed out.
• Starting S7-PLCSIM.exe manually returns "Component 'S7WSIMAX.DLL' is not correctly registered."
• Windows 7 Action Center flags PLCSIM as an "incompatible application."

3. Root Cause Analysis

The base V5.4 installer was compiled against the Windows XP / Server 2003 MSI stack (msi.dll 3.1). When executed on Windows 7 (msi.dll 5.0), three preconditions break:

1. Custom action DLL resolution: The base setup calls LoadLibraryW on S7WINST.DLL using a relative path that is invalid under WOW64 path redirection on 64-bit Windows 7 Ultimate.
2. UAC manifest mismatch: The V5.4 manifest declares requestedExecutionLevel level="asInvoker" even though the installer requires elevation. Windows 7 silently splits the token, and the custom action runs without the per-machine registry rights it requires.
3. OS version guard: The bootstrapper checks GetVersionEx against a fixed list that does not include Windows 6.1 (the major.minor reported for Windows 7). The check returns FALSE, and the installer aborts before extracting payload files.

Service Pack 5 + Update 1 re-compiles the bootstrapper with the GetVersionExW replacement, embeds a Windows 7-aware manifest, and rebases the custom action paths. Applying the patch resolves all three classes of fault.

4. Prerequisites

Verify the workstation meets the following matrix before running the corrected setup:

STEP 7 must be installed before S7-PLCSIM. The PLCSIM setup scans for STEP 7 registry keys at HKLM\SOFTWARE\Siemens\AUTSW\STEP7 and aborts with "STEP 7 V5.4 SP5 or higher not found" if the parent is missing.

5. Step-by-Step Resolution

5.1 Download the Corrective Patch

1. Navigate to the Siemens Industry Online Support entry 51884628: S7-PLCSIM V5.4: Service Pack 5 incl. Update 1.
2. If the primary link is unreachable, fall back to the secondary Siemens entry 27033164 which archives earlier V5.4 SP5 media and historic service packs.
3. Authenticate with your Siemens Customer Center account (free registration). The download is approximately 240 MB and is delivered as S7-PLCSIM_V54_SP5_HF1.exe.
4. Verify the SHA-1 checksum published on the support page matches the downloaded file before executing.

5.2 Clean Pre-Installation State

1. Open Control Panel → Programs and Features.
2. If a previous failed PLCSIM instance is listed, right-click → Uninstall. If the uninstaller errors out, proceed to step 3.
3. Stop the Windows Installer service: net stop msiserver from an elevated command prompt.
4. Delete stale MSI temp files: del /q "%TEMP%\MSI*.tmp" and del /q "%TEMP%\_is*.tmp".
5. Remove residual registry branches: open regedit and delete HKLM\SOFTWARE\Siemens\AUTSW\PLCSIM and HKCR\CLSID\{XXXX}* entries that reference S7WSIMAX.DLL.
6. Restart Windows to flush file locks before continuing.

5.3 Apply the Service Pack

1. Right-click S7-PLCSIM_V54_SP5_HF1.exe → Run as administrator.
2. Accept the license agreement; the dialog re-routes through the S7WINST.DLL Windows-7-aware custom action.
3. Select the installation path. The default is C:\Program Files\Siemens\Automation\PLCSIM (32-bit) or C:\Program Files (x86)\Siemens\Automation\PLCSIM (64-bit). Do not redirect to a path with spaces or non-ASCII characters.
4. When prompted, choose Update existing installation. The patcher detects the V5.4 base and increments the binary version in place.
5. Allow the patcher to register COM components. This step takes 30–90 seconds and is silent on success.
6. Click Finish. Do not restart immediately if the wizard requests it — restart manually after step 4.

5.4 Post-Installation Verification

1. Reboot Windows 7 Ultimate.
2. Launch STEP 7 V5.5 → SIMATIC Manager → Options → Simulate Modules. The PLCSIM window should open without error.
3. Open a test S7-300 project, compile hardware (HW Config), and download to PLCSIM. The CPU should reach RUN within 5 seconds.
4. Confirm binary file version: right-click s7wsimax.dll → Properties → Details → Product version must read 5.4.5.1.
5. Verify COM registration: from elevated CMD run regsvr32 /s "%ProgramFiles%\Siemens\Automation\PLCSIM\bin\s7wsimax.dll" (adjust the path for 64-bit). The command should return without error.

6. Verification Matrix

The following matrix maps each reported symptom to the verification check that proves it is resolved:

7. Edge-Case Workarounds

7.1 Windows 7 64-Bit Path Redirection

If the patcher returns "Bad Image" (HRESULT 0x8007000B) on Windows 7 64-bit, the most likely cause is WOW64 path redirection intercepting the 32-bit PLCSIM binaries. Disable redirection for the install session:

1. Open an elevated command prompt.
2. Navigate to the patch directory: cd C:\Users\<user>\Downloads
3. Run: %SystemRoot%\SysWOW64\cmd.exe /c "S7-PLCSIM_V54_SP5_HF1.exe"

This forces the 32-bit cmd host to launch the 32-bit installer in its native bitness, eliminating redirected registry writes.

7.2 Corrupted MSI Cache

If the Event Viewer records MsiInstaller Event ID 1012 (missing source file), the Windows Installer cache at %WINDIR%\Installer is corrupt. Repair it with:

1. Run msizap G from the Windows Installer SDK to clear orphan registry entries.
2. Reinstall the patch from a clean state.

7.3 Concurrent Antivirus Interception

Some endpoint protection suites (Symantec Endpoint Protection 12.x, McAfee VirusScan Enterprise 8.8) quarantine S7WINST.DLL during the unpack phase. Add an exclusion for %TEMP%\Siemens and the target PLCSIM directory before running the patcher.

7.4 Missing Visual C++ Runtime

If the patcher fails with "The procedure entry point _gmtime64_s could not be located in the dynamic link library msvcrt.dll", install the Visual C++ 2005 SP1 Redistributable (x86 for 32-bit, x64 for 64-bit) before retrying.

8. Compatibility Matrix and Migration Path

S7-PLCSIM V5.4 is the last classic-STEP 7 generation of the simulator. Projects created in STEP 7 V5.5 + PLCSIM V5.4 SP5 can be migrated to TIA Portal V13+ using the S7-PLCSIM included with the TIA installation. The migration is one-way: TIA Portal cannot run V5.4 standalone PLCSIM.

For new deployments on Windows 7 Ultimate, PLCSIM V5.4 SP5+HF1 remains the only legally-supported simulation runtime. The TIA Portal V13/V14 runtimes officially support Windows 7 SP1 only with S7-1200/1500 PLCSIM, not with the V5.4 classic line.

9. Field-Commissioning Checklist

1. Confirm base V5.4 install: reg query "HKLM\SOFTWARE\Siemens\AUTSW\PLCSIM" /v Version returns 5.4.0.0.
2. Apply Service Pack 5 + Hotfix 1: launch S7-PLCSIM_V54_SP5_HF1.exe as administrator.
3. Reboot and confirm file version: s7wsimax.dll = 5.4.5.1.
4. Test simulation: open SIMATIC Manager, create S7-300 station with CPU 314, download empty OB1, confirm RUN.
5. Test MPI/Profibus virtual interface: PLCSIM → PLC → MPI Access Points → verify PLCSIM(Internal) is bound to TCP/IP Auto.
6. Document the patch level in the project header to satisfy audit requirements.

10. Common Error Code Reference

11. FAQ