Siemens Industry Online Support
Siemens AG
Entry type: FAQ, Entry ID: 40228606, Entry date: 04/20/2012

Why do you get a prompt to restart MS Windows after installing STEP 7 V11, although the PC has already been booted?

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A restart is required after installing or uninstalling STEP 7 V11, because the system files blocked in the current mode have to be updated or deleted, or if DLL files are opened by other applications at the same time.

The Microsoft Windows operating system uses the DLL (Dynamic Link Library) files to reduce the memory space required by an application on the hard disk and in the main memory. Any program code is stored in a separate file on the hard disk and is loaded only once into the main memory

  • if the program code is needed by more than one application or
  • if multiple programs need the same program library.

If multiple applications have different versions or if the required version is missing in a program, conflicts might arise if the same DLL files are needed.

In MS Windows, the installation routines or updates make a list of which system or DLL files have to be moved, renamed or deleted at the next system start and enter them in the registry code "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager". The entries in the "PendingFileRenameOperations" value are processed the next time the system is started and the value is deleted.

It might happen that for system reasons MS Windows does not delete these entries in the "PendingFileRenameOperations" value during the boot procedure. However, after a restart Windows nevertheless recognizes that files have been registered for renaming or deleting and that the installation or deinstallation has not yet been completed. You get the message:

  • "Please reboot before installing any more programs".

If you restart your PC and the entries in the value "PendingFileRenameOperations" are once again not deleted during the boot procedure, the behavior described above is repeated. This can happen in all Microsoft Windows operating systems.

Delete the registry code "PendingFileRenameOperations". A detailed procedure for this remedy is available in Entry ID 8861819.

This entry contains information for editing the registry. You should make a backup copy of the registry before editing it. More information on making a backup copy, restoring and editing the registry is available in the Microsoft Knowledge Base in Entry ID 256986. Incorrect use of the registry editor can cause serious problems that affect the complete system and make it necessary to reinstall the operating system. You use the registry editor at your own risk.

Additional Keywords
DLL conflict, Reboot, permanent

Security information
In order to protect plants, systems, machines and networks against cyber threats, it is necessary to implement – and continuously maintain – a holistic, state-of-the-art industrial security concept. Siemens’ products and solutions constitute one element of such a concept. For more information about industrial security, please visit

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