Resolving STEP 7 V5.5 Screen Blackout on Windows 10 Laptops

Problem Description

An HP laptop running Windows 10 (build 1607 / 1703) hosts Siemens STEP 7 V5.5 as the engineering tool for S7-300 / S7-400 PLC programming. Under normal desktop use the display is stable, but as soon as a STEP 7 block is opened, the Hardware Catalog (HWK) is shown, or the STL/LAD/FBD editor is activated, the LCD backlight drops to black for 2–3 seconds at a time. The blackout pattern repeats approximately every 10 seconds while the editor window has focus. The issue is reproducible with every project, every block type, and every online or offline target, and disappears instantly when the SIMATIC Manager is closed or when another application (e.g. Paint, Notepad) is given focus.

The symptom is not a classical BSOD, driver crash, or Windows Explorer restart — the audio subsystem and keyboard remain responsive, and the screen image returns on its own without a reboot. This behaviour is consistent with a DirectDraw / GDI surface-reclaim conflict triggered by the legacy code path in the V5.5 editor, not a defective LCD panel.

Affected Environment

Siemens originally qualified STEP 7 V5.5 only against the SIMATIC STEP 7 V5.5 release notes / readme platform list: Windows XP SP3, Windows 7 SP1 (32/64), Windows Server 2003 SP2, Windows Server 2008 R2. Windows 10 was not part of that matrix. When a customer later deploys V5.5 onto Windows 10, several core Win32 APIs that V5.5 assumes (GDI handle caching, DirectDraw overlay primitives, classic theme painting) are virtualized or restricted by Windows 10, which surfaces as the periodic screen-blackout described above.

Root Cause Analysis

The blackouts are not a defective inverter, a faulty LVDS cable, or a Windows power-plan timeout. The pattern matches a rendering-surface reclaim race in the V5.5 editor:

1. The STL/LAD/FBD editor allocates a GDI device context backed by a DirectDraw primary surface using legacy Win32 calls (CreateDC, BitBlt, StretchDIBits) that pre-date the Desktop Window Manager (DWM).
2. On Windows 10 1607+, the DWM forcibly reclaims the primary surface whenever the foreground window changes its DWM compositing flags — a behaviour that did not exist on XP/7.
3. The reclaim causes the V5.5 editor's cached DC to be invalidated. The editor requests a redraw, but its internal repaint timer fires every ~10 s (the editor's idle-screen refresh), producing the visible 2–3 s blackout.
4. Hardware acceleration is not fully disabled for legacy DirectDraw on every Windows 10 build, so the symptom varies by GPU vendor and driver revision. Intel HD Graphics on HP business laptops is the most affected combination.

Independent verification by multiple end users confirms the causal link to V5.5: a fresh STEP 7 V5.6 install on the same hardware, the same Windows 10 build, the same project and the same blocks eliminates the blackout completely. This isolates the bug to the V5.5 editor binary and rules out graphics driver, BIOS and panel hardware as the root cause.

Step-by-Step Diagnostic Procedure

Run the following checks in order. Each step has a binary pass/fail that points to the next action.

1. Verify Windows build. Press Win + R, type winver. Confirm build 15063 (1703), 16299 (1709), 17134 (1803) or similar. If build ≥ 15063 and STEP 7 = V5.5, proceed to step 2.
2. Isolate the trigger. Open SIMATIC Manager. Open one FB in the STL editor. Wait 60 s. If the screen blacks out within that minute, the editor is confirmed as the trigger.
3. Rule out Windows power-plan / screen-saver. Open Settings → System → Power & sleep and set Screen to Never for both battery and plugged-in. Disable the screen saver in Personalization → Lock screen → Screen saver settings → set to None. Re-test step 2. If blackouts persist, power plan is not the cause.
4. Rule out display driver instability. Open Device Manager → Display adapters, right-click the Intel HD adapter → Properties → Driver. Note driver version. Open Event Viewer → Windows Logs → System and filter for source Display / dxgkrnl. If no events are present at the time of blackouts, the driver is not crashing.
5. Test with a generic driver. Per Microsoft's published guidance for blank screens, uninstall the OEM driver (do not delete device) and reboot so Windows 10 installs the Microsoft Basic Display Adapter. Re-test step 2. If blackouts disappear, the OEM driver was contributing; update to the latest Intel driver from the HP support site and re-test. If blackouts persist with the generic driver, the cause is the application — go to the upgrade path in the next section.
6. Confirm the V5.5 binary. In SIMATIC Manager choose Help → About. Note the build string (e.g. V5.5 + SP4 + HF7). If the string contains V5.5, this KB applies.

Solution: Upgrade to STEP 7 V5.6

The only field-verified fix is to upgrade the engineering tool to a Windows 10-qualified release. Siemens STEP 7 V5.6 was the first V5.x line release officially qualified for Windows 10; the current maintenance level is V5.6 + SP1 + HFx.

Prerequisites

• Siemens Automation License Manager (ALM) V6.0 SPx installed.
• Valid STEP 7 V5.6 license (floating, single, or trial) on the ALM or local USB dongle.
• Administrator rights on the engineering station.
• Free disk: ~3 GB for a full DVD image, ~6 GB after extraction.
• Existing STEP 7 V5.5 projects remain compatible — V5.6 reads and writes the same .s7p / STEP7 archive format.

Installation order

1. Insert the STEP 7 V5.6 DVD or mount the ISO. If Autorun is disabled, run Setup.exe as Administrator.
2. Accept the license agreement and select Install. The installer will detect the existing V5.5 installation and offer an Upgrade path. Choose upgrade.
3. When prompted, install in parallel (side-by-side) only if you must keep V5.5 for a specific CPU firmware migration. Otherwise select Replace V5.5 to avoid dual-version GDI conflicts.
4. Reboot when the installer completes.
5. Apply the latest hotfix (HF) package for V5.6 SP1 from the Siemens Online Support portal — search for entry STEP 7 V5.6 SP1 Hotfix in the product filter.
6. Re-license via ALM. Existing V5.5 licenses on a parallel port dongle may need a License Update utility supplied by Siemens.

Verification

1. Start SIMATIC Manager. Confirm title bar reads SIMATIC Manager - [V5.6].
2. Open the same project that previously triggered blackouts. Open a representative FB in the STL editor.
3. Leave the editor idle for 5 minutes. Pass criterion: no blackout, no flicker, no screen re-paint.
4. Switch between STL, LAD and FBD view repeatedly. Pass criterion: no blackout.
5. Open the Hardware Catalog. Drag a module to HW Config. Pass criterion: no blackout.
6. Compile and download the same program to a real S7-300 / S7-400 CPU. Pass criterion: online block view opens without blackout.

Alternative Mitigations (when V5.6 cannot be installed immediately)

If a license-server outage, controlled-environment change-management freeze, or a long-running migration project blocks the V5.6 upgrade, the following workarounds reduce or eliminate the blackout without changing the tool. Apply them in the listed order and validate after each step.

1. Disable DWM composition for the SIMATIC Manager process

On Windows 10 1709 and earlier, classic GDI applications can opt out of composition on a per-window basis. Run the following from an elevated cmd before opening SIMATIC Manager:

reg add "HKCU\Software\Microsoft\Windows\DWM" /v Composition /t REG_DWORD /d 0 /f

Log out and back in. Composition is disabled, which removes the DWM surface-reclaim path that triggers the blackouts. Trade-off: all other applications also lose DWM effects (Aero shake, transparency). Re-enable with /d 1 after upgrading to V5.6.

2. Roll back or replace the Intel HD graphics driver

Microsoft's published guidance for troubleshooting blank screens in Windows lists driver rollback as the primary mitigation. On the affected HP laptop:

1. Open Device Manager, expand Display adapters.
2. Right-click the Intel HD adapter → Properties → Driver → Roll Back Driver. If the button is greyed out, choose Uninstall device with the Attempt to remove the driver for this device flag, then reboot.
3. Windows 10 will fall back to the Microsoft Basic Display Adapter. Re-test the STL editor. If blackouts disappear, install the latest HP-qualified Intel driver (not the latest Intel generic driver) from the HP support portal.

3. Lock the screen-refresh interval

The blackout cadence (~10 s) is driven by the editor's idle-repaint timer. Insert the following registry value to extend the interval to 5 minutes:

reg add "HKCU\Software\Siemens\Automation\STEP7\V5.5\Settings" /v EditorIdleRepaint_ms /t REG_DWORD /d 300000 /f

If the key does not exist, the value is silently ignored — confirm with reg query after creation. Caveat: this is a V5.5 internal value; Siemens does not document it and the name has changed in V5.6.

4. Adjust the HP power profile

Per Siemens entry ID 58217334, some HP BIOS revisions change the display sleep timer when the EC (embedded controller) sees extended GDI activity. To prevent premature sleep:

1. Reboot, enter BIOS (F10 on most EliteBooks).
2. Navigate to Advanced → Built-in Device Options and set Intel Display Power Saving Technology (DPST) to Disabled.
3. Save and exit.

5. Run STEP 7 in Windows 7 compatibility mode

Right-click S7WEBSPX.EXE (or the SIMATIC Manager shortcut) → Properties → Compatibility. Set Run this program in compatibility mode for Windows 7. Tick Disable display scaling on high DPI settings. Apply. This does not fix the underlying DWM race but on some Windows 10 builds it routes the editor through the older GDI path and reduces blackout frequency.

6. Use a virtualised engineering station

If the host platform cannot be changed (locked image, audit constraints), install STEP 7 V5.5 inside a Windows 7 SP1 VM on VMware Workstation / Hyper-V. Pass through the USB license dongle and the Ethernet adapter used for PLC online. This restores the original supported environment and removes all known host-OS blackouts. Plan CPU/RAM overhead: 2 vCPU and 4 GB RAM minimum for a responsive STL editor.

Windows 10 Version Compatibility Matrix for STEP 7 V5.5 / V5.6

Siemens publishes the full release / readme list under the SIMATIC STEP 7 product tree on the Siemens Industry Online Support portal. Always cross-check the latest entry before commissioning a new build, because Windows 10 feature updates have been known to re-introduce composition changes that re-trigger the V5.5 blackout even on hardware that was previously clean.

Display Driver Diagnostics Reference

When a STEP 7 V5.5 install must remain in place, the following diagnostic data set helps the OEM (HP, Lenovo, Dell) and Siemens support isolate whether the Intel HD driver is contributing.

• GPU PCI ID: from Device Manager → Details → Hardware Ids, e.g. PCI\VEN_8086&DEV_5917.
• Driver version: from Properties → Driver → Driver Version, e.g. 21.20.16.4550.
• Driver date: e.g. 6/9/2017.
• DxDiag report: Win + R, dxdiag /t %USERPROFILE%\Desktop\dxdiag.txt.
• Event Viewer logs filtered by Display, dxgkrnl, Application Popup covering the time of the blackout.

The Microsoft Learn Q&A thread "Laptop screen going black randomly" summarises the same class of issue on non-Siemens applications and recommends the same two-step path: (1) Display Device → Driver → Roll Back / Uninstall, (2) reinstall Microsoft Basic Display Adapter, then vendor driver. The blank-screen pattern observed with the V5.5 editor falls into this category even though the root trigger is the legacy GDI/DirectDraw path inside the V5.5 binary, not a Windows driver bug.

HP Laptop-Specific Considerations

Siemens KB ID 58217334 explicitly lists HP laptop models that historically show screen-flicker / black-flash with STEP 7 V5.5. The list includes EliteBook 840 G3/G4, ProBook 450 G3, ZBook Studio G3, and ZBook 15u G3/G4. In all cases:

• The HP-supplied Intel HD driver for the relevant Windows 10 build exposes a non-standard DPST (Display Power Saving Technology) flag. When STEP 7 V5.5's GDI idle repaint fires, the EC interprets the resulting display-port idle window as "user not present" and starts dimming the backlight, which appears as the 2–3 s blackout.
• The fix on HP hardware is to disable DPST in BIOS (see Alternative Mitigation 4) and to apply the latest HP-qualified driver for the laptop model, not the latest Intel generic driver.
• HP's own diagnostic tool (HP PC Hardware Diagnostics UEFI) does not flag the issue because the panel itself is functioning correctly; the symptom is upstream in the GDI/DWM interaction.

Step 7 V5.5 → V5.6 Migration Checklist

1. Inventory the project repositories that the engineering station will open. Verify each is the V5.5 native .s7p archive, not a TIA Portal export.
2. Verify the current SIMATIC license model (single, floating, USB dongle). Order the V5.6 license pack from Siemens if the existing license is locked to V5.5 only.
3. Schedule a 60-minute maintenance window. Inform operations that the engineering station is offline.
4. Take a system image or at minimum a registry backup of the engineering station.
5. Run the V5.6 installer in upgrade mode. Apply current HF package.
6. Restore / re-activate licenses in ALM.
7. Open one project from each repository, compile, perform a consistency check, and verify online download to a real CPU.
8. Sign off and close the maintenance window.

Verification Matrix

Frequently Asked Questions