WinCC Flexible SP5 Stuck on Loading: Windows 10 Compatibility Fix

Problem: WinCC Flexible 2008 SP5 Hangs on the Splash Screen

After uninstalling WinCC Flexible 2008 SP3 and installing SP5 on a Windows 10 engineering workstation, the tool starts to load and never finishes. The splash window stays open, the process remains resident, and the project explorer never appears. The same symptom appears when the workstation is rolled back to SP3, which indicates that the operating system - not the service pack level - is the root cause. Engineers who reach this state usually have a working HMI license, an intact project archive, and a Windows 10 host that cannot be downgraded because it is shared with other engineering tools.

Root Cause Analysis

WinCC Flexible 2008 was released in 2008 and updated through several service packs. The official compatibility matrix lists support for Windows XP SP3, Windows Vista Business/Ultimate, and Windows 7 Professional/Ultimate/Enterprise (32-bit and 64-bit where indicated). SP3 is not released for Windows 10, and the engineering software was never updated to declare Windows 8.1 or Windows 10 as supported. When the OS returns values that WinCC Flexible does not expect - missing installer shims, .NET CLR 2.0 binding failures, or unhandled SQL Server named-pipes negotiation - the loader hangs instead of throwing a clean exception.

Three independent failure modes are typical:

1. OS version check. The bootstrapper validates the Windows version against an internal table. On Windows 10 the version string "10.0" is greater than any value the table contains, the install completes, but runtime checks fail silently.
2. .NET CLR initialization. WinCC Flexible 2008 hard-codes CLR 2.0 binding. Windows 10 ships with .NET 4.x as the in-box CLR and does not auto-install CLR 2.0. If .NET 3.5 SP1 is not enabled, mscoree.dll returns 0x80131700 (COR_E_FILELOAD) and the splash screen never closes.
3. MSDE / SQL Server Express instance. The engineering database is a SQL Server Express instance installed by the WinCC Flexible setup. Windows 10 disables the named-pipes protocol by default; the instance starts but the ODBC layer hangs in SQLGetInfo for 60 s, after which the GUI times out.

Supported Windows Versions for WinCC Flexible 2008 SP5

The only authoritative source is the live Siemens KB. The summary below is an example of what to expect - always cross-check the row for your service pack against the official table before you commit to a deployment plan.

When the matrix shows "Not released" for Windows 10, Siemens has not validated the engineering software against that OS. The software may still install, but unsupported behaviour - including splash hangs, missing panels in the catalog, and silent compile failures - is expected.

Pre-Repair Checklist

1. Confirm the Windows 10 build with winver (Start -> Run -> winver). Record the full version string, for example Version 22H2 (OS Build 19045.xxxx).
2. Capture an msinfo32 report: msinfo32 /report %USERPROFILE%\Desktop\sysinfo.txt.
3. List installed .NET versions: reg query "HKLM\SOFTWARE\Microsoft\NET Framework Setup\NDP" /s. Look for v3.5 and v4.
4. List installed SQL instances: reg query "HKLM\SOFTWARE\Microsoft\Microsoft SQL Server" /s | findstr InstalledInstances and sc query state= all | findstr /i "wincc siemens".
5. List remaining WinCC Flexible folders: dir /s "C:\Program Files\Siemens\Automation" and dir /s "C:\ProgramData\Siemens\Automation".
6. Snapshot the registry hive: reg export "HKLM\SOFTWARE\Siemens\Automation" %USERPROFILE%\Desktop\reg_backup.reg /y.
7. Back up every *.hmi project, library, script, and recipe/audit log to a network share before any repair attempt.
8. Capture a Procmon boot trace of HmiES.exe for 60 s and save as HmiES_boot.pml for offline analysis if the repair fails.

Repair Method 1 - Switch to the Trial License

The fastest in-place recovery is to swap the production license for the official trial license, which does not phone home and skips the activation handshake that is the most common hang point on Windows 10.

1. Close WinCC Flexible completely. Open services.msc and stop the SQL instance installed by WinCC Flexible (look for a service whose name contains WinCC) and any service whose name starts with Siemens HMI or ALM.
2. Open Automation License Manager (Start -> Siemens Automation -> Automation License Manager). Select the local computer in the left pane.
3. Right-click the WinCC Flexible license and select Move license.... Write the license back to a USB dongle or to a .lic file.
4. Download the WinCC Flexible 2008 SP5 trial from KB 100777999 - WinCC Flexible 2008 SP5 Trial. The trial is a 21-day full-feature engineering license that does not require activation.
5. Install the trial to a separate folder, for example D:\Siemens_Trial\WinCC Flexible 2008 SP5. Use the existing install path only after the previous service pack has been completely removed.
6. Launch the trial, then re-attach the production license using Automation License Manager -> Install license....

Repair Method 2 - Compatibility Mode and Shims

When the workstation is locked to Windows 10 and the engineering software must run there, configure the launcher with explicit compatibility shims. This is a workaround, not a fix; expect to re-apply it after every Windows 10 feature update.

1. Navigate to the WinCC Flexible install folder (typically C:\Program Files\Siemens\Automation\WinCC Flexible\HmiES) and locate HmiES.exe. Right-click -> Properties -> Compatibility tab.
2. Enable Run this program in compatibility mode for: and select Windows 7.
3. Enable Run this program as an administrator.
4. Open Compatibility Troubleshooter from the same dialog. Choose Troubleshoot program -> The program worked in earlier versions of Windows but won't install or run now -> Windows 7. Save settings.
5. Open an elevated command prompt and apply the compatibility shim database directly:

   forfiles /p "%ProgramFiles%\Siemens\Automation" /m HmiES.exe /c "cmd /c reg add \"HKCU\Software\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layers\" /v \"@path\" /t REG_SZ /d \"WIN7RTM RUNASADMIN\" /f"

6. Enable the .NET 3.5 feature on demand. From an elevated PowerShell:

   Enable-WindowsOptionalFeature -Online -FeatureName "NetFx3" -All -NoRestart

   Windows 10 1903 and newer removes the in-box .NET 3.5 source. Supply -Source "D:\sources\sxs" if the network is restricted.
7. Grant the engineering install tree the required ACLs so the application virtualisation layer does not redirect writes:

   icacls "C:\Program Files\Siemens\Automation" /grant *S-1-5-11:(OI)(CI)(RX) /T
   icacls "C:\Program Files\Siemens\Automation" /grant *S-1-5-32-545:(OI)(CI)(M) /T

8. Enable the named-pipes protocol for the SQL instance installed by WinCC Flexible. Open SQL Server Configuration Manager (sqlservermanager10.msc for the SQL 2008 engine that ships with SP5), expand SQL Server Network Configuration, select the instance, right-click Named Pipes -> Enable, and restart the SQL service.

Repair Method 3 - Full Clean Reinstall

When the install is corrupted across registry, services, and files, the only path to a clean state is a tracked uninstall, manual cleanup, and reinstall.

1. Open Programs and Features (appwiz.cpl). Uninstall, in this order:
   1. Siemens HMI License Server
   2. WinCC Flexible SQL Server (the SQL instance installed by the WinCC Flexible setup)
   3. WinCC Flexible 2008 SP5
   4. WinCC Flexible 2008 SP4 (if listed)
   5. WinCC Flexible 2008 SP3 (if listed)
   6. WinCC Flexible 2008
   7. Siemens Automation License Manager
2. Manually delete the install trees:

   rmdir /s /q "C:\Program Files\Siemens\Automation\WinCC Flexible"
   rmdir /s /q "C:\Program Files (x86)\Siemens\Automation\WinCC Flexible"
   rmdir /s /q "C:\ProgramData\Siemens\Automation\WinCC Flexible"
   rmdir /s /q "%LOCALAPPDATA%\Siemens\WinCC Flexible"
   rmdir /s /q "%APPDATA%\Siemens\WinCC Flexible"

3. Delete the WinCC Flexible registry hives:

   reg delete "HKLM\SOFTWARE\Siemens\Automation\WinCC Flexible" /f
   reg delete "HKLM\SOFTWARE\Wow6432Node\Siemens\Automation\WinCC Flexible" /f
   reg delete "HKCU\Software\Siemens\Automation\WinCC Flexible" /f

4. Stop and delete the orphaned SQL instance:

   sc query state= all | findstr /i wincc
   sc stop "<service_name_from_query>"
   sc delete "<service_name_from_query>"

   Replace <service_name_from_query> with the actual service name returned in the previous step. Then remove the SQL data directories the install created.
5. Reboot. Verify no leftover Siemens services remain: sc query state= all | findstr /i siemens.
6. Install .NET Framework 3.5 SP1 from the Windows Features dialog or from an offline installer.
7. Install the SQL instance component shipped with WinCC Flexible (a separate setup option, not a generic SQL Server Express install). Watch the MSI log for the named-pipes configuration step; the instance must start.
8. Install WinCC Flexible 2008 SP5. Do not install SP3 over the top of SP5 - SP3 is an older service pack and will not upgrade cleanly.
9. Apply the Automation License Manager and re-attach the production license.

Repair Method 4 - Virtual Machine Deployment

When WinCC Flexible must remain available and Windows 10 is non-negotiable on the host, the supported deployment is a virtual machine running a Windows OS that is on the official matrix. This is the configuration Siemens field engineers recommend for HMI engineering on locked-down Windows 10 hosts.

1. Provision a Windows 7 Professional SP1 (x86) VM. Allocate 2 vCPU, 4 GB RAM, 60 GB vHDD. Disable Hyper-V's Credential Guard for the VM; the WinCC Flexible license server can refuse to start otherwise.
2. Enable .NET Framework 3.5 SP1 from Programs and Features -> Turn Windows features on or off.
3. Install the WinCC Flexible SQL Server component, then WinCC Flexible 2008 SP5. Accept the default instance name suggested by the setup.
4. Map the network project share: net use Z: \\fileserver\HMI_Projects /persistent:yes. Place *.hmi files on the share so multiple engineers can co-edit via the source-control plugin.
5. If the production license is on a USB dongle, pass the USB controller to the VM. Soft dongles (.lic files) can be activated on the host and exported to the VM.
6. Set the VM power plan to High performance. The Balanced plan can suspend the VM clock and trigger a 21-day trial warning on the engineering license.

Long-Term Path - Migration to TIA Portal

Engineering for legacy Siemens panels is fully covered by TIA Portal for the OP/TP/MP 177, 277, 377, and Mobile Panel 177/277 series. Projects must be migrated using the WinCC Flexible Migration Tool included with TIA Portal.

1. Inventory every panel under engineering. Sort by article number (the 6AV6 prefix denotes HMI devices; verify the exact article number against the official Siemens catalog before ordering spares):

   6AV6 641-1xxxx-0xx  -> OP 77B family
   6AV6 642-0xxxx-0xx  -> TP 170A/B family
   6AV6 642-1xxxx-0xx  -> TP 177A/B family
   6AV6 643-1xxxx-0xx  -> MP 177 family
   6AV6 644-0xxxx-0xx  -> OP 270 / TP 270 family
   6AV6 644-1xxxx-0xx  -> OP 277 / TP 277 family
   6AV6 645-0xxxx-0xx  -> MP 270 family
   6AV6 645-1xxxx-0xx  -> MP 370 / MP 377 family

2. Check the migration matrix in the TIA Portal help. Panels with image < 12.0 may require a firmware update before migration; the WinCC Flexible runtime version on the panel is in the project properties.
3. Open the WinCC Flexible project in the engineering software, then in TIA Portal select Project -> Migrate WinCC Flexible project.... The tool reports convertible items, ignored items (e.g. non-migratable ActiveX controls), and items needing manual fix-up.
4. Compile the migrated project. Address any VBScript API differences; the TIA Portal WinCC scripting object model is documented in the TIA Portal help under Visual Basic Scripting -> Reference.
5. Update the panel firmware using ProSave or the TIA Portal Update operating system function. The panel may not need a firmware change; check the result column of the migration report.

Verification and Commissioning Checks

1. Launch HmiES.exe from the start menu. The splash screen must close in < 10 s on a Windows 7 SP1 host and in < 25 s on a Windows 10 host with the compatibility shim applied.
2. Open a small project (for example one of the WinCC Flexible samples installed under the engineering software's Samples directory).
3. From the Project -> Compiler... menu, run Check consistency. The compiler should complete without errors.
4. Open Runtime -> Start runtime and verify the panel emulator window opens.
5. Stop the runtime. Open Tools -> ProSave and perform a backup of the project to a network share.
6. Open Event Viewer -> Windows Logs -> Application and confirm no new .NET Runtime or SQL Server errors within the last 5 minutes.
7. On Windows 10 hosts, schedule a recurring task to re-apply the WIN7RTM shim after feature updates: schtasks /create /sc onevent /ec Application /mo "*[System[Provider[@Name='Microsoft-Windows-Winlogon'] and EventID=21]]" /tn "Reapply_WinCC_Flexible_Shim" /tr "reg add \"HKCU\Software\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layers\" /v \"C:\Program Files\Siemens\Automation\WinCC Flexible\HmiES\HmiES.exe\" /t REG_SZ /d \"WIN7RTM RUNASADMIN\" /f"

Troubleshooting Matrix

FAQ