Changing the Installation Drive Path and Bypassing Locked Default Directory in SIMATIC PCS 7 Setup

In SIMATIC PCS 7 (v8.0 through v9.x), the installer locks the installation path to drive C:\Program Files (x86)\SIEMENS and disables the 'Browse' button whenever any pre-existing Siemens software component or registry key is detected on the host operating system. To install PCS 7 onto an alternate drive partition (such as D: or E:), engineers can either perform a User-Defined Package installation on a pristine Windows system with zero prior Siemens software, or copy the installation media to disk, modify the DefaultInstallPath parameter inside Setup.ini, and execute the modified installer.

Why the SIMATIC PCS 7 Installer Locks the Default Drive

When running Setup.exe from the SIMATIC PCS 7 installation media:
* In the Installation Type dialog, engineers frequently find the Browse button disabled (greyed out) and the target path locked to C:\Program Files (x86)\SIEMENS.
* The Underlying Reason: Siemens architecture enforces a strict single-root hierarchy. If any component (e.g. Automation License Manager, SIMATIC Logon, or a base device driver) was previously installed on drive C:, the master setup prohibits splitting binary components across multiple drive letters.
* All shared COM servers, type libraries, and common APIs must reside under the exact same filesystem tree.

Prerequisites for Custom Path Selection via GUI

To allow the setup wizard to display an active Browse button:
1. The Windows operating system must be a pristine, fresh installation with zero Siemens software packages installed.
2. In the setup wizard, select Package installation (or User-defined installation).
3. If no pre-existing Siemens registry keys (HKEY_LOCAL_MACHINE\SOFTWARE\Siemens) exist, the setup enables the Browse button, permitting the selection of D:\Program Files (x86)\SIEMENS.

The Setup.ini Modification Workaround (Forcing Alternative Drives)

If the Browse button remains unavailable or if a secondary high-speed SSD partition must be enforced:

[Phase 1: Copy Installation Media to Local Disk]
   │  • Create a local folder: C:\PCS7_Setup   │  • Copy the entire contents of PCS 7 DVD 1 (and DVD 2 if merged) into this folder
   ▼
[Phase 2: Edit Setup.ini Configuration]
   │  • Open: C:\PCS7_Setup\Setup.ini in a text editor (e.g. Notepad++)
   │  • Search for the parameter: DefaultInstallPath
   │  • Original Line: DefaultInstallPath=C:\Program Files (x86)\SIEMENS
   │  • Modified Line: DefaultInstallPath=D:\Program Files (x86)\SIEMENS
   │  • Save and close Setup.ini
   ▼
[Phase 3: Launch Setup with Custom Defaults]
   │  • Execute: C:\PCS7_Setup\Setup.exe as Administrator
   │  • The installer automatically targets drive D: as the primary root directory
   └─► All bundled packages install seamlessly onto the alternate partition!

System Drive Considerations for WinCC SQL Databases

The table below outlines filesystem storage considerations across different drive partitions:

Directory / ComponentDefault PathRecommended Custom PathStorage Performance RequirementSiemens Program BinariesC:\Program Files (x86)\SIEMENSD:\Program Files (x86)\SIEMENSFast SSD (50 GB+ free space)WinCC SQL Database InstanceC:\Program Files (x86)\Microsoft SQL ServerRemains on OS System Drive (C:)High IOPS NVMe SSDEngineering Project DataC:\Program Files (x86)\SIEMENS\STEP7\s7projD:\PCS7_Projects\Dedicated data partition with daily backupsWinCC Tag / Alarm ArchivesTarget_OS\ArchiveManager\Dedicated fast partition (E:\WinCC_Archives\)RAID 1/10 array for sustained write logging

Verification

To confirm that PCS 7 has installed onto the intended alternate drive:
1. Once installation completes, open Windows Explorer and navigate to D:\Program Files (x86)\SIEMENS.
2. Verify that core folders—STEP7, WinCC, CFC, and S7SCL—are populated with binary files.
3. Launch SIMATIC Manager; select Help -> About -> Installed Software; verify that all component paths point to drive D:.
4. Open Automation License Manager; confirm that license keys on drive C: are recognized and validated cleanly by programs running on drive D:.
5. Create and compile a test CFC chart; confirm that compilation binaries execute without missing file exceptions.

Limitations and Operational Precautions

Even when PCS 7 program files are installed on drive D: or E:, Microsoft SQL Server and core Windows shared prerequisites (such as Microsoft .NET Framework and Visual C++ runtimes) will still install certain components onto the system drive (C:). Ensure that drive C: retains at least 25 GB of free space regardless of the installation target drive.

Engineer FAQ

Why is the Browse button greyed out in PCS 7 setup?

Because the installer detected existing Siemens registry keys or software components on drive C:, locking the path to preserve single-root shared libraries.

Does changing DefaultInstallPath in Setup.ini void Siemens warranty?

No. Editing Setup.ini to define default administrative deployment paths is an officially documented Siemens deployment methodology.

Can I move existing PCS 7 installations to another drive by copying files?

No. Never move installed Siemens software by dragging folders in Windows Explorer. Thousands of Windows registry keys point to absolute file paths; moving folders will break the installation completely.