Siemens PCS 7 CFC Toolbar Missing: Recovery Guide for V7.1 SP1

1. Problem Statement: Disappearing CFC Toolbar in PCS 7 V7.1 SP1

The Continuous Function Chart (CFC) editor bundled with Siemens PCS 7 V7.1 SP1 is built on the STEP 7 V5.5 runtime shell. When the editor is closed, the docking window manager persists the last known position of every toolbar, palette, and child window to a combination of the Windows registry and the local project workspace. If a user drags a toolbar outside the main editor frame, or the toolbar is placed on a secondary monitor that is later disconnected, the docking state can be written to a coordinate that is no longer reachable on the current display configuration. The result is a CFC editor that opens normally, the chart canvas renders, but the toolbar is simply not visible anywhere on the visible desktop area.

This behavior is not a software crash and is not indicative of corrupt project data. The chart, the SFC/CFC compilation results, and the connected AS stations are intact. The defect is a UI layout state stored in the engineering workstation profile. The engineering impact is still severe: the operator cannot insert new blocks, toggle runtime, open the chart-in-chart navigator, or invoke the cross-reference functions without the toolbar. Commissioning and online maintenance operations on the AS can be blocked until the toolbar is restored.

Typical symptoms reported in field cases include:

• Main CFC editor window opens, chart is visible, but no toolbar, status bar, or library tree is rendered.
• Toggling View → Toolbar from the menu has no visible effect.
• Reinstalling the CFC optional package alone does not bring the toolbar back.
• Connecting a second monitor reveals the toolbar docked at the extreme edge of the previously-attached display.
• Resolution changes between sessions can shift the off-screen position by a few hundred pixels but rarely bring the toolbar into the visible desktop region.

Because PCS 7 V7.1 SP1 predates the SIMATIC Manager layout reset that was introduced in later PCS 7 versions (V8.0 SP1 onward), the legacy layout state must be corrected by one of the recovery paths described below.

2. Affected Software Versions and Engineering Environment

The toolbar placement bug is reproducible on the following commonly deployed engineering stacks:

The issue also surfaces on PCS 7 V7.0, V7.0 SP1, and V7.1 (without SP1) because the CFC docking manager in S7CFCUI.DLL is shared across these versions. Newer PCS 7 V8.x and V9.x releases ship a hardened S7CFCUI.DLL that clamps the docking coordinates to the primary monitor, which is why the symptom is most frequently reported on the V7.1 SP1 generation.

Engineering stations with a single monitor are not immune. A second monitor that was once attached (a docking station, a KVM switch, or a brief projector connection) is enough to write off-screen coordinates into the layout cache. The condition is then triggered by the next session even though the second monitor is no longer present.

3. Root Cause: Off-Screen Window Positioning in CFC Editor

CFC stores toolbar docking state under the current Windows user hive:

HKEY_CURRENT_USER\Software\SIEMENS\CFC\V7.1\Layout
HKEY_CURRENT_USER\Software\SIEMENS\CFC\V7.1\Toolbar
HKEY_CURRENT_USER\Software\SIEMENS\Automation\WinCC\Layout\CFC

Typical offending values look like the following (decimal coordinates captured from a real V7.1 SP1 ES with two 1920×1080 monitors in landscape):

ToolbarMainWnd   REG_SZ  x=-1920;y=80;w=200;h=24;visible=1
PaletteLibrary   REG_SZ  x=-1910;y=120;w=320;h=480;visible=1
Navigator        REG_SZ  x=-1500;y=0;w=240;h=600;visible=1

The negative x value is the smoking gun. The Windows docking engine in V7.1 SP1 does not validate the coordinate against the active monitor configuration before serializing the layout. The next time CFC initializes, it restores the toolbar at x = -1920, which is exactly one full HD monitor width to the left of the visible desktop. The visible=1 flag still says the toolbar should be drawn, so View → Toolbar will not toggle it on because the editor believes it is already visible.

The bug is amplified by two other factors:

1. Per-user cache. The layout is written into %APPDATA%\SIEMENS\CFC\Layout.bin and into the registry under HKCU. Reinstalling the CFC optional package does not touch either location because both are owned by the logged-in user, not by the system account under which the installer runs.
2. Monitor disconnect events. Windows fires WM_DISPLAYCHANGE when a monitor is removed, but the CFC docking manager in V7.1 SP1 ignores the message. The layout is therefore not migrated to the remaining display.

Recovery is therefore a matter of either (a) making the off-screen coordinate reachable, (b) deleting the cached layout, or (c) resetting the docking state through a documented cleanup procedure.

4. Quick Recovery: Resolution Change and Single-Monitor Trick

The fastest no-toolbox recovery uses a Windows display configuration change to bring the off-screen coordinate back into the visible area. This is the procedure that resolved the original case on a dual-screen engineering station.

1. Close SIMATIC Manager and any open CFC/SFC editors.
2. Open Display Settings from the Windows Control Panel (right-click desktop → Personalize → Display → Change display settings on Windows 7; right-click desktop → Screen resolution on Windows XP/Server 2003).
3. If a second monitor is currently attached, change Multiple displays to Show desktop only on 1. If only one monitor is present, change the resolution to a lower value (for example drop from 1920×1080 to 1280×1024) and apply.
4. Press Enter to confirm the new resolution when Windows prompts. The toolbar coordinate that was off-screen will fall into the visible area, usually pinned near the top edge of the desktop.
5. Re-launch SIMATIC Manager, open the CFC chart, and use the mouse to drag the relocated toolbar back to its normal dock position inside the editor frame.
6. Close the CFC editor. The toolbar position is now re-serialized with valid coordinates for the active display configuration.
7. Restore the original display configuration. Open the CFC editor a second time to confirm the toolbar is still in the correct position.

5. Multi-Monitor Repositioning: Bringing the Toolbar Back

If a second monitor is available, the off-screen toolbar can be recovered without changing resolution by extending the desktop across both displays.

1. Connect the second monitor to the engineering station and power it on.
2. In Screen Resolution, set Multiple displays to Extend these displays. Apply.
3. Set the secondary monitor as the left-most display in the layout diagram. This places the previously negative x range onto the physical pixels of the secondary monitor.
4. Open the CFC editor. The toolbar will appear docked against the left or top edge of the secondary monitor.
5. Drag the toolbar onto the primary monitor and dock it at the desired location. Press OK on any Save layout prompt.
6. Close and reopen the editor to confirm the layout is persistent.

To move toolbars programmatically without dragging, use the Window menu of the CFC editor and select Reset window layout if available. On V7.1 SP1 this menu item is conditional on the file %ProgramFiles%\SIEMENS\Automation\CFC\Bin\CFCReset.mnu being present. If the entry is missing, the registry key HKCU\Software\SIEMENS\CFC\V7.1\Layout\Reset can be set to 1 (DWORD) before launching the editor; the CFC process will reset all docked children to their default factory positions on first launch and delete the key.

6. Registry-Based Recovery for the CFC Toolbar Layout

If the display trick is not available (for example, the engineering station is in a clean room with a fixed single-monitor kiosk configuration), the layout state can be corrected directly in the Windows registry.

1. Close all SIMATIC Manager, CFC, and SFC processes. Verify in Task Manager that S7CFCEX.EXE and S7BMPEX.EXE are not running.
2. Open regedit.exe as the affected user (administrator rights are not required because the keys live under HKCU).
3. Navigate to HKEY_CURRENT_USER\Software\SIEMENS\CFC\V7.1. Export the entire branch to a .reg file for rollback.
4. Delete the subkeys Layout, Toolbar, and WindowState. These three subkeys store every docked child window position, including the toolbar, the library palette, and the chart navigator.
5. Also delete the binary cache file %APPDATA%\SIEMENS\CFC\Layout.bin and the per-chart *.lay files in the project directory:

del /q "%APPDATA%\SIEMENS\CFC\Layout.bin"
del /q /s "<ProjectDir>\CFC\*.lay"
del /q /s "<ProjectDir>\SFC\*.lay"

6. Re-launch the CFC editor. The docking manager will re-create the layout subkeys using the default factory coordinates on the primary monitor.

For engineering stations where multiple users share the same Windows profile, the corrective action must be repeated for every user hive (HKEY_USERS\<SID>\Software\SIEMENS\CFC\V7.1). A scripted deployment is appropriate for fleets of 10 or more ES workstations.

7. Windows User Profile Isolation Test

Before performing any destructive cleanup, confirm that the toolbar is not simply hidden in a corrupted user profile by logging in as a different Windows user with sufficient rights to launch SIMATIC Manager.

1. Log out of the affected user account.
2. Log in as a local administrator or as a test engineer account that has previously worked with the same PCS 7 project.
3. Launch SIMATIC Manager, open the same CFC chart.
4. If the toolbar is visible in the second user account, the defect is isolated to the original user's hive. The registry cleanup described in Section 6 is the correct fix.
5. If the toolbar is still missing in the second account, the defect is at the project level. Inspect the *.lay files referenced in Section 6 and the chart's @CFC_WinPos attribute in the S7 program.

The user-isolation test is non-destructive and should always be performed first when the engineering station is in a production environment and a rollback path through reinstalling Windows is not acceptable.

8. Repair Installation via Windows Control Panel

Before attempting a complete uninstall, run a repair install of the CFC optional package. The repair process re-extracts the default *.mnu and *.dll files from the source media and re-registers the COM objects.

1. Insert the original PCS 7 V7.1 SP1 DVD (or mount the ISO at a known drive letter, for example D:\).
2. Open Control Panel → Programs and Features on Windows 7, or Add or Remove Programs on Windows XP/Server 2003.
3. Select SIMATIC PCS 7 - CFC from the list. Click Repair (Windows 7) or click Change and choose Repair installation (Windows XP).
4. Follow the prompts. The installer will detect the existing installation path and re-deploy the binaries without touching the project database or the user registry hive.
5. Reboot when prompted.
6. Open the CFC editor. If the toolbar is still missing, proceed to Section 9 (complete uninstall) and Section 6 (registry cleanup).

The repair install is effective when the missing toolbar is caused by a corrupted binary (for example, an anti-virus product quarantined a .dll). It is not effective when the layout state in HKCU is the root cause, which is the dominant failure mode on V7.1 SP1.

9. Complete Removal of STEP 7 and PCS 7 Components

If repair does not bring the toolbar back, perform a full removal of STEP 7 and the PCS 7 optional packages, including the manual registry sweep that the Siemens installer does not perform by default.

1. Back up the entire engineering project from <ProjectDir> to an external drive.
2. Export the complete HKLM\Software\SIEMENS and HKCU\Software\SIEMENS registry branches for offline reference.
3. Run the Siemens uninstaller from Start → Programs → Siemens Automation → SIMATIC → STEP 7 → Uninstall. The official removal procedure is documented in Siemens Knowledge Base entry ID 77391787 and removes STEP 7, S7-PLCSIM, the CFC, SFC, and S7-GRAPH optional packages, and the SIMATIC Manager shell.
4. After the automatic uninstall completes, manually delete the directories:

rd /s /q "C:\Program Files\SIEMENS\Automation"
rd /s /q "C:\Program Files\Common Files\SIEMENS"
rd /s /q "%APPDATA%\SIEMENS"
rd /s /q "%LOCALAPPDATA%\SIEMENS"

5. Run regedit.exe and remove the keys:

HKEY_LOCAL_MACHINE\SOFTWARE\SIEMENS
HKEY_CLASSES_ROOT\*\shellex\ContextMenuHandlers\S7ShellExt
HKEY_CURRENT_USER\Software\SIEMENS

6. Reboot the engineering station.
7. Reinstall PCS 7 V7.1 SP1 from the original media, then re-apply the latest hotfix (HF) package from the Siemens support portal. The current HF rollup for V7.1 SP1 at the time of writing is HF11.
8. Restore the project from the backup created in step 1.
9. Open a test CFC chart and verify the toolbar is present in its default factory position.

10. Verification Steps After Toolbar Recovery

Use the following checklist to confirm that the toolbar recovery is complete and that the fix is persistent across reboots, user logons, and display configuration changes.

11. Prevention: Locking the CFC Layout and Best Practices

Once the toolbar is recovered, harden the engineering station against recurrence with the following field-proven practices.

• Disable hot-plugging of secondary monitors. Configure the Windows group policy User Configuration → Administrative Templates → Desktop → Desktop → Prevent changes to Display Settings to Enabled on engineering ES workstations.
• Set a fixed resolution. Lock the engineering station to a single resolution and color depth through the same group policy. The recommended baseline for V7.1 SP1 is 1920×1080 @ 32 bpp, single monitor, 100% DPI.
• Use the documented layout reset key from Section 5 to script a startup-time fix on the engineering image. Deploy a LayoutReset.reg file through the Siemens SIMATIC Management Console (SiVArc) startup script.
• Centralize user profiles. Use mandatory Windows roaming profiles or a Siemens-specific profile template (PCS 7 V7.1 SP1 supports per-role profile templates in the Engineering Tool) so that all controls engineers start with a known-good HKCU layout.
• Block manual dragging of toolbars. For production ES workstations that are operated by maintenance technicians, deploy the policy HKCU\Software\SIEMENS\CFC\V7.1\LockLayout=1 (DWORD) to prevent users from dragging toolbars off the visible desktop.
• Schedule periodic layout file backups. Add %APPDATA%\SIEMENS\CFC to the standard ES backup set. A healthy Layout.bin file from a peer engineer can be copied into a corrupted user profile to restore the toolbar without a full uninstall.
• Plan for migration to PCS 7 V9.x. The V8.0+ CFC docking manager validates window coordinates against the active monitor configuration and is not subject to the off-screen bug. For new plants, design the engineering station specification around V9.0 SP2 or later.

Adopting the above practices reduces the occurrence of the missing-toolbar symptom to near zero on a properly maintained engineering station fleet.