WinCC V6.2 SP2 Project Open Failure on Windows XP SP3 Registry

1. Problem Overview

Operators and engineers running SIMATIC WinCC V6.2 SP2 on a workstation whose Windows XP installation was auto-upgraded from SP2 to SP3 by corporate IT report a sudden, repeatable failure when launching the WinCC Explorer. The application starts, the splash screen appears, and then the project open / create dialog returns an access-denied or COM initialization error before any project can be opened or created. Newly created projects cannot be saved, and previously working .mcp project files now refuse to load.

The failure is not caused by project corruption, license issues, or DCS hardware. It is a host-platform incompatibility triggered by the Windows XP Service Pack 3 update. This article documents the exact diagnostic sequence, the KB319740 registry shim that restores operation, and the supported upgrade path to WinCC V6.2 SP3 when the registry workaround is not approved by plant IT.

2. Affected Software Matrix

The reference matrix is derived from the official Siemens product compatibility list. For current production deployments, refer to the SIMATIC WinCC V8 product page and the SIMATIC HMI catalog (ST 80 / ST 80 PC) for the latest supported operating-system matrix.

3. Root Cause Analysis

WinCC V6.2 SP2 was certified against the Windows XP SP2 kernel (NT 5.1.2600.2180+) and the matching DCOM/COM+ configuration. Service Pack 3 changed several internal structures:

• Updated MSCTF.dll and MSI.DLL versions broke the version check performed by the WinCC project open routine.
• The DCOM default authentication hardening added in XP SP3 alters the launch permissions on the WinCC OPC/DCOM servers, so the Explorer process cannot bind to the configured COM apartment even when the user is a member of SIMATIC HMI.
• The HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows XP\SP3 hive does not contain the KB319740 update entry that WinCC V6.2 SP2 looks for during project open to validate platform conformance.

Siemens documents this combination as an unsupported configuration. The official workaround is either to remain on Windows XP SP2, to upgrade to WinCC V6.2 SP3, or to apply the registry entry documented in Siemens support entry FAQ entry 31694897.

4. Diagnostic Procedure

Run the following checks before changing anything. They confirm that the failure is the XP SP3 incompatibility and not a user-rights, license, or DCS-side problem.

1. Capture the exact error text from the WinCC Explorer dialog. Save the screenshot or copy the message string. The canonical message references the project open / project create action and points to a missing component or denied access.
2. Confirm the Windows XP Service Pack level.

   winver

   From the Start > Run dialog. The About Windows screen reports Service Pack 3 when the incompatibility is active.

3. Confirm the WinCC install level.

   reg query "HKLM\SOFTWARE\Siemens\Automation\WinCC\Versions" /s

   The VersionInstalled value reports 06.02.02.XX for WinCC V6.2 SP2.

4. Verify user rights.

   Control Panel > Administrative Tools > Computer Management
    > Local Users and Groups > Groups
     -> Administrators: user must be a direct member
     -> SIMATIC HMI:     user must be a direct member
     -> Siemens TIA Users (V11+ only)

   If the user is not a member of SIMATIC HMI, the WinCC project open / create routines fail with the same family of errors. Confirm membership before applying the registry workaround; otherwise the symptom returns on the next logon.

5. Inspect the update hive.

   reg query "HKLM\SOFTWARE\Microsoft\Updates\Windows XP\SP3" /s

   If the hive is missing the KB319740 subkey, you have confirmed the WinCC V6.2 SP2 / XP SP3 incompatibility described in section 3.

5. Solution A - Registry Workaround (KB319740)

The fastest path back into production is to add the KB319740 update entry under the Windows XP SP3 update hive. WinCC V6.2 SP2 queries this subkey during project open and, when present, the platform-version check returns a value the application recognizes as acceptable.

1. Log on as the local administrator (or any user that is a direct member of Administrators).
2. Open the registry editor.

   Start > Run > regedit

3. Navigate to:

   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows XP\SP3

4. Create a new key with the name KB319740:

   Reg Add "HKLM\SOFTWARE\Microsoft\Updates\Windows XP\SP3\KB319740" /ve

5. Under KB319740, create the Description and PackageName string values that WinCC V6.2 SP2 expects:

   Reg Add "HKLM\SOFTWARE\Microsoft\Updates\Windows XP\SP3\KB319740" /v Description /t REG_SZ /d "Security Update for Windows XP (KB319740)"
   Reg Add "HKLM\SOFTWARE\Microsoft\Updates\Windows XP\SP3\KB319740" /v PackageName /t REG_SZ /d "Update\KB319740\KB319740.CAB"

6. Close regedit and re-launch WinCC Explorer.

The project open / create dialog should now succeed against the existing project database and against a fresh .mcp project.

6. Solution B - Upgrade to WinCC V6.2 SP3

If the registry shim is not approved by plant IT, upgrade the WinCC installation to V6.2 SP3, which is fully certified against Windows XP SP3.

1. Capture the current WinCC project archive:

   Start > SIMATIC > WinCC > Project Duplicator
    -> select the running project
    -> choose "Duplicate for upgrade"
    -> save as .pck

2. Stop all WinCC services:

   net stop "S7DOS"
   net stop "CCArchiveManager"
   net stop "CCAlgRtTaskManager"
   net stop "CCProjectManager"

3. Insert the WinCC V6.2 SP3 DVD. From the autorun menu, choose Install WinCC > Upgrade existing installation.
4. After the upgrade completes, restart the host and re-open the project.
5. Re-apply the project archive if needed and verify alarms, scripts, and tag logging.

7. Solution C - Downgrade to Windows XP SP2

When the WinCC V6.2 SP2 install must remain untouched (validated against a regulatory baseline, for example), restore the host to Windows XP SP2. The procedure is destructive; do not attempt it without a full system-image backup and a documented change window.

1. Capture a full system image using the plant-standard imaging tool.
2. Boot the XP SP2 installation media.
3. Choose Repair > Install Windows to revert the binary tree to SP2 while preserving the partition layout.
4. Re-install the WinCC V6.2 SP2 service packs and hotfixes from the project archive.
5. Block the XP SP3 update from re-applying via Group Policy:

   gpedit.msc
    -> Computer Configuration
      -> Administrative Templates
        -> Windows Components
          -> Windows Update
            -> "Do not display 'Install Updates and Shut Down' option"
            -> "Configure Automatic Updates" = Disabled

This option is rarely used today because most plants are already on Windows 7 / Windows 10 / Windows Server 2016+ with a current WinCC release.

8. User Rights and SIMATIC HMI Group Configuration

Even after applying the registry shim or the SP3 upgrade, WinCC Explorer enforces the following security configuration. If any of these is missing, the project open / create routine still fails.

Power-shell verification (run as administrator):

$user = [System.Security.Principal.WindowsIdentity]::GetCurrent().Name
$admins = Get-LocalGroupMember -Group "Administrators" | Select-Object -ExpandProperty Name
$simatic = Get-LocalGroupMember -Group "SIMATIC HMI" | Select-Object -ExpandProperty Name
if ($admins -contains $user) { "Admin OK" } else { "Add user to Administrators" }
if ($simatic -contains $user) { "SIMATIC HMI OK" } else { "Add user to SIMATIC HMI" }

9. Verification

After applying any of the three solutions, validate the repair in the following order. Each step has a clear pass / fail criterion that allows the engineer to roll back if a step regresses.

1. Project open test. Launch WinCC Explorer > Open > Open Project. Open the production .mcp. Pass criterion: the project opens without dialog errors and the Activated state is reachable.
2. Project create test. Launch WinCC Explorer > File > New Project. Create a single-user project named VERIFY_XXX. Pass criterion: the project wizard completes and the project tree is editable.
3. Runtime activation test. Activate the new project. Pass criterion: runtime starts, the configured start picture is displayed, and no CCProjectManager event-log errors are written.
4. OPC DA round trip. Use OPC Scout (or the WinCC-internal OPC DA client) to read a tag and write it back. Pass criterion: read returns current value, write is acknowledged within the configured update time.
5. Event log clean check.

   eventvwr.msc
    -> Application log
      filter Source = "CCProjectManager", "CCAlgRtTaskManager", "WinCC"

   Pass criterion: no Error or Warning entries in the last 15 minutes of operation.

6. Registry hive persistence. Reboot the host and confirm the KB319740 subkey still exists.

   reg query "HKLM\SOFTWARE\Microsoft\Updates\Windows XP\SP3\KB319740"

10. Prevention and Best Practices

• Block SP3 in GPO for legacy WinCC hosts. Engineering workstations running WinCC V6.2 SP2 should be moved to a dedicated OU with the XP SP3 update denied in WSUS or SCCM. The registry shim is a fix, not a long-term defense.
• Standardize on WinCC V7.4 SP1 or V7.5. For greenfield or migration projects, deploy the latest WinCC release supported on the host OS. See the SIMATIC WinCC V8 overview and the SIMATIC WinCC entry on Wikipedia for cross-version context.
• Maintain a tested restore image. Always retain an image of the engineering host taken immediately after WinCC V6.2 SP2 installation. This image is the fastest recovery when IT pushes an incompatible update.
• Centralize change notifications. Subscribe to the Siemens ProductCERT and SIMATIC Customer Support RSS feeds to be alerted when a WinCC release loses or gains platform support.
• Document the SIMATIC HMI group membership. Add the group configuration to the project's Backup / Recovery documentation so that re-imaged hosts are restored to a known-good state.

11. Long-term Migration Path

Plants that still operate WinCC V6.2 SP2 on Windows XP have an end-of-support horizon for both products. Plan the migration in three waves:

1. OS wave - move engineering and runtime stations from Windows XP to Windows 10 LTSC 2019 / Windows 10 IoT Enterprise LTSC 2021. Validate WinCC version compatibility before the OS cutover.
2. SCADA wave - upgrade WinCC V6.2 SP2 to the latest WinCC V7.x release that matches the new OS. Migrate .mcp projects using Project Duplicator and re-validate tags, scripts, alarms, and archives.
3. Architecture wave - move from single-station WinCC to a client-server deployment, optionally add WinCC V8 for new lines. The SIMATIC WinCC V8 release introduces multi-user redundancy, native 64-bit support, and modern web clients.

The combination of the registry shim, the SIMATIC HMI group check, and the SP3 upgrade covers all known failure modes reported in the field. For deployments where the registry shim is acceptable to IT, WinCC V6.2 SP2 can remain in service on XP SP3 until the planned migration window opens.

12. FAQ