Resolving 'Error Occurred Creating the OS Objects' in the PCS 7 New Project Wizard

The error 'Error occurred creating the OS objects' during the execution of the PCS 7 'New Project Wizard' is predominantly caused by NTFS disk compression or encryption enabled on the target project directory. Microsoft SQL Server (which hosts WinCC runtime and configuration databases) strictly prohibits mounting or creating database files (.mdf and .ldf) on compressed NTFS volumes. When the PCS 7 wizard attempts to generate the default WinCC Operator Station project, SQL Server throws an internal file creation error (OS error 5118), prompting the wizard to abort. To resolve this error, right-click the project folder (or entire storage drive), select Properties > Advanced, uncheck 'Compress contents to save disk space', apply the changes to all subfolders and files, verify that the logged-on user belongs to the 'SIMATIC HMI' user group, and rerun the wizard.

Executive Summary

Creating a new multi-user or single-station PCS 7 project via the 'New Project Wizard' automates the instantiation of the multiproject structure, S7 program containers, CFC charts, and the WinCC Operator Station (OS). However, if the destination directory has NTFS compression or encryption attributes active, the wizard fails during the OS object creation phase with the fatal message 'Error occurred creating the OS objects'. Because WinCC uses Microsoft SQL Server as its embedded database engine, and SQL Server does not support compressed storage, the database creation script fails. Removing NTFS compression, validating Windows user group memberships (SIMATIC HMI, SIMATIC NET), and confirming SQL Server service availability restores proper wizard operation.

Architecture and Fundamental Mechanics

The PCS 7 'New Project Wizard' (s7wzwd.exe / s7pcreator.exe) executes an automated sequence to scaffold automation assets:

Multiproject and AS Creation: The wizard creates the root multiproject directory, master data library, and SIMATIC 400 station database using standard STEP 7 file structures.
WinCC Project Generation: When scaffolding the OS, the wizard calls the WinCC project creation API (CCProjectServer.exe / WinCCExplorer.exe). WinCC instructs the local Microsoft SQL Server instance (MSSQL$WINCC) to execute CREATE DATABASE scripts for the configuration database (<ProjectName>.mdf / <ProjectName>.ldf).
The NTFS Compression Conflict:
* Microsoft SQL Server is architected for high-performance direct I/O and transaction logging. It explicitly disallows creating database files on NTFS compressed partitions (SQL Server error 5118: 'The file cannot be compressed because it resides on a database that is read-only or in a compressed directory').
* If the user selects a project path such as C:\Program Files (x86)\Siemens\Step7\s7proj\ or D:\PCS7_Projects\ where the parent folder has inherited the Windows blue-text 'Compress contents to save disk space' attribute, SQL Server immediately rejects the file creation request.
* The WinCC API catches the database creation exception and returns a failure code to the STEP 7 wizard, which surfaces the generic error: 'Error occurred creating the OS objects'.
Secondary Factors:
* User Group Permissions: If the logged-on Windows account is not a member of the local SIMATIC HMI and SIMATIC NET groups, SQL Server denies the account permission to create databases.
* SQL Server Instance State: If the SQL Server (WINCC) service is stopped, disabled, or corrupted by incompatible Windows updates, OS generation fails.

Step-by-Step Implementation Procedure

Follow these steps to eliminate the OS object creation error in the PCS 7 wizard:

Disable NTFS Compression on Project Directories:
* In Windows File Explorer, navigate to the target directory where the project is being created (e.g., D:\Projects or C:\Program Files (x86)\Siemens\Step7\s7proj).
* Right-click the folder and select Properties.
* On the General tab, click Advanced....
* In the Advanced Attributes dialog, uncheck Compress contents to save disk space.
* Ensure Encrypt contents to secure data is also unchecked.
* Click OK, then click Apply.
* When prompted, select Apply changes to this folder, subfolders and files and click OK.
Verify SQL Server (WINCC) Service Status:
* Press Win + R, type services.msc, and press Enter.
* Locate the service named SQL Server (WINCC).
* Verify that the status is Running and the Startup Type is set to Automatic.
* If stopped, right-click and select Start.
Verify Windows User Group Memberships:
* Press Win + R, type lusrmgr.msc, and press Enter to open Local Users and Groups.
* Click Groups and verify that your Windows user account is a member of:
- SIMATIC HMI
- SIMATIC NET
- Administrators
- If recently added to these groups, you must log off and log back in (or reboot) for group token changes to take effect.
Check Directory Path Constraints:
* Ensure the project directory path does not contain special characters (such as @, #, $, %, or non-ASCII characters) and that the total path length is well under the 260-character Windows limit.
Rerun the PCS 7 New Project Wizard:
* Open SIMATIC Manager and launch File > 'New Project' Wizard....
* Select the CPU type, OS configuration, and target path where compression was disabled.
* Click Finish; verify that the project structure, AS station, and WinCC OS project generate successfully without errors.

Verification

After disabling NTFS compression and verifying SQL Server, execute the wizard. Observe the progress bar as it generates the OS objects. Upon completion, confirm that the multiproject tree opens in SIMATIC Manager with both the AS station and OS station fully populated. Open the OS station in WinCC Explorer; confirm that the WinCC project opens cleanly with all graphic screens, tag management, and alarm logging editors accessible.

Limitations and Operational Precautions

Never compress any drive partition hosting Siemens PCS 7, WinCC, or Process Historian databases. Compressing database volumes causes severe database fragmentation, transaction log corruption, and high CPU overhead during runtime. Always ensure at least 20 GB of uncompressed, free disk space on the system drive (C:) and project drive.

Engineer FAQ

Why does SQL Server refuse to work on compressed folders?

SQL Server requires direct sector-aligned disk access and write-ahead logging to guarantee ACID transaction durability. NTFS compression alters physical block layouts dynamically, which can corrupt database write consistency.

How can I visually tell if a folder is compressed in Windows?

In Windows File Explorer, compressed folders and files often display their names in blue text, or have a two-arrow icon overlay in the top-right corner of the file icon.

Can I create the AS project first and add the OS manually later?

Yes. If the wizard fails, you can create a standard project with only the AS station, uncompress the folder, and then manually insert a SIMATIC PC Station with a WinCC Application.

What if SQL Server (WINCC) fails to start entirely?

If the SQL Server service cannot start, check the Windows Event Viewer under Application logs. Common causes include corrupt master database files or permission changes on the SQL data directory.