Resolving WinCC 7.2 'Network Not Available' Installation Error

1. Problem Overview: WinCC 7.2 Setup Halt on Network Probe

Siemens WinCC V7.2 (and adjacent releases such as WinCC V7.3, PCS 7 V8.0/V8.1/V8.2, and the TIA Portal WinCC Professional packages) performs a hard network-stack validation at the moment the Setup.exe process initializes. When the operating system cannot answer that probe with a usable TCP/IP path, the installer aborts with a Win32 dialog:

The network is not available. Do you want to reestablish the connection to the network?

The dialog fires before the language selection screen and before any package-specific checks (SQL Server, Message Queuing, Web Navigator, etc.). The same prompt has been reproduced on:

• Windows 7 Professional SP1 32-bit and 64-bit
• Windows Server 2008 R2 SP1 (used as the engineering station for PCS 7)
• Windows 7 SP1 hosted inside VMware Workstation / ESXi (PCS 7 V8.2)
• Windows 10 (when WinCC V7.x is forced to install outside the supported matrix)

Because the error surfaces during the bootstrap of the installer rather than during the actual file copy, rebooting, re-downloading, or re-burning the DVD typically does not clear the condition. The root cause is always a missing or incomplete network subsystem on the target machine.

2. Root Cause Analysis: Why WinCC Setup Requires an Active Network

WinCC 7.x setup is built on Microsoft Windows Installer (MSI) combined with the Siemens Automation License Manager and the SIMATIC Shell COM components. During the Setup.exe bootstrap the installer:

1. Enumerates the network adapters via iphlpapi.dll (GetAdaptersInfo, GetAdaptersAddresses).
2. Resolves the local computer name via NetBIOS and DNS.
3. Registers a temporary RPC endpoint to coordinate multi-installer sub-sessions.
4. Launches the Siemens SIMATIC Shell discovery service (Siemens.Simatic.S7Comm.Net) which subscribes to UDP/137-139 (NetBIOS) and UDP/5353 (mDNS) for plant discovery.

Any one of these calls returning ERROR_NETWORK_UNREACHABLE (0x000004C3 / 1219), ERROR_NO_NETWORK (0x000004C6 / 1222), or RPC_S_SERVER_UNAVAILABLE (0x000006BA / 1722) aborts the bootstrap before the user sees the EULA. Common triggers recorded in field cases are:

3. Pre-Installation Prerequisites Checklist

Before launching Setup.exe on any WinCC 7.2 target, validate the following baseline. All items must be green:

1. Operating system: Windows 7 SP1 (32-bit or 64-bit) or Windows Server 2008 R2 SP1. Confirm with winver.
2. User account: member of the local Administrators group. UAC adjusted to the lowest level for the install only.
3. TCP/IP stack active: at least one adapter must be enabled and bound to IPv4. The loopback adapter is acceptable as a last resort.
4. Computer name: 15 characters or less, no special characters, no leading digit, no reserved words (CON, PRN, AUX). Microsoft naming conventions apply.
5. Windows Firewall: enabled or disabled consistently. A half-configured firewall blocks the SIMATIC Shell UDP probes.
6. .NET Framework 3.5: enabled with .NET 2.0 and .NET 3.0 child features. WinCC V7.2 setup bootstrap is a .NET 2.0 CLR application.
7. Message Queuing (MSMQ): installed (Server feature). Required by WinCC alarm logging runtime and redundancy partners.
8. SQL Server 2008 R2 / 2014: either pre-installed or provided by the WinCC setup media.
9. Internet Information Services (IIS): enabled (WinCC WebNavigator / WebUX prerequisites).
10. Free disk space: minimum 10 GB for the engineering system, 20 GB recommended.

4. Step-by-Step Resolution Procedure

4.1 Step 1 — Verify the Network Adapter State

1. Open Control Panel → Network and Sharing Center → Change adapter settings.
2. Confirm at least one adapter (physical or virtual) shows Enabled.
3. If only a wireless adapter exists and the workstation has no SSID in range, connect an Ethernet cable and disable Wi-Fi to avoid roaming artifacts.
4. Open cmd.exe as Administrator and run:

   netsh interface show interface
   ipconfig /all
   ping 127.0.0.1
   ping <own-hostname>

5. All three commands must succeed. A failed ping 127.0.0.1 indicates the TCP/IP driver is corrupted and the network stack must be reset (see §6).

4.2 Step 2 — Enable Network Discovery and Required Windows Services

If Network Discovery is turned off, the local computer is invisible to its own Network folder and the SIMATIC Shell probe fails. Restore it as follows:

1. Control Panel → Network and Sharing Center → Change advanced sharing settings.
2. For the current profile (typically Private or Domain), select Turn on network discovery and Turn on file and printer sharing.
3. Open services.msc and set the following services to Automatic and Started:

   Service Name	Display Name	Startup Type
   FDResPub	Function Discovery Resource Publication	Automatic
   SSDPSRV	SSDP Discovery	Automatic
   DNS Client	DNS Client	Automatic
   NSI	Network Store Interface Service	Automatic
   NetTcpPortSharing	Net.TCP Port Sharing Service	Manual
   MSMQ	Message Queuing	Automatic

4. Restart the workstation.
5. After reboot open Windows Explorer → Network. The local computer icon must appear; if it shows Network Discovery is turned off the services did not start.

4.3 Step 3 — Enable .NET Framework 3.5 (Sp1)

WinCC 7.2 setup bootstrap and the SIMATIC Shell configuration UI are written against the .NET 2.0 CLR. Without .NET 3.5 the bootstrap throws CLR20r3 (Event ID 1026 in the Application log) and rolls back, which Siemens setup masks as a network error.

1. Open Control Panel → Programs and Features → Turn Windows features on or off.
2. Tick .NET Framework 3.5 (includes .NET 2.0 and 3.0).
3. Click OK. Windows will request the source files if no internet connection is available; point the dialog to D:\sources\sxs (the sxs folder on the Windows 7 DVD) or to C:\Windows\WinSxS.
4. For offline install the administrative command is:

   DISM /Online /Enable-Feature /FeatureName:NetFx3 /All /Source:D:\sources\sxs /LimitAccess

5. Reboot. Confirm with reg query "HKLM\SOFTWARE\Microsoft\NET Framework Setup\NDP\v3.5" /v Install — value must be 0x1.

4.4 Step 4 — Set a Static IP When No DHCP Server Exists

WinCC setup probes the network during bootstrap and stalls if it cannot resolve a default gateway or DNS server. On an isolated engineering station, configure a static IPv4 address before launching setup:

1. Open Network and Sharing Center → adapter → Properties → IPv4.
2. Use an address from a documentation-only range, e.g. 192.168.0.100 / 255.255.255.0.
3. Set the preferred DNS server to 127.0.0.1 or to a valid DNS server; do not leave the field empty.
4. Save and run ipconfig /registerdns followed by ping %COMPUTERNAME%.

4.5 Step 5 — Re-verify SIMATIC Shell Visibility

1. Click Start → Programs → Siemens Automation → SIMATIC → SIMATIC Shell.
2. Confirm the local station appears in the right pane under Accessible nodes within 30 s.
3. If nothing appears, the network adapter is still treated as disconnected. Disable Allow the computer to turn off this device to save power on the NIC's Power Management tab.

4.6 Step 6 — Launch Setup as Administrator

1. Right-click Setup.exe and select Run as administrator.
2. If the prompt appears again, click No (the installer treats "No" as a graceful abort and lets you inspect logs). Open C:\ProgramData\Siemens\Automation\Logfiles\Setup\RASETUP.log.
3. If the prompt must be cleared, ensure all steps above are completed before re-trying.

5. VMware-Specific Remediation

WinCC 7.x is officially supported on physical Windows 7 hosts only, but PCS 7 V8.2 training environments often run inside VMware. The host network adapter can be removed (for example, after laptop undocking) and VMware silently un-binds the virtual NIC, triggering the same error.

1. Open VM → Settings → Network Adapter.
2. Confirm the adapter is connected and the connection type is Bridged or NAT (bridged preferred for engineering networks).
3. From inside the guest, run devmgmt.msc and ensure the VMware Accelerated AMD PCNet Adapter (or VMXNET3 in newer guests) is enabled.
4. If still failing, install VMware Tools (or open-vm-tools) to refresh the virtual NIC drivers.
5. Re-enable .NET 3.5 — VMware guests frequently ship with only .NET 4.x enabled.

6. Resetting a Corrupted TCP/IP Stack

If ping 127.0.0.1 itself fails, the TCP/IP driver must be reset. Use the netsh int ip reset and Winsock catalogue rebuild sequence:

netsh winsock reset catalog
netsh int ipv4 reset reset.log
netsh int ipv6 reset reset.log
ipconfig /flushdns
ipconfig /release
ipconfig /renew
shutdown /r /t 0

7. Reading the Setup Log Files

The Siemens setup writes detailed traces to C:\ProgramData\Siemens\Automation\Logfiles\Setup\. The most useful files are:

Search each file for keywords ERROR_NETWORK_UNREACHABLE, ERROR_NO_NETWORK, 0x80004005 (E_FAIL), 0x800700C1 (bad image), and RPC_S_SERVER_UNAVAILABLE. The first occurrence of a non-zero Win32 error usually pinpoints the failing subsystem.

8. Common Error Codes Mapped to Causes

9. Verification Procedure

After the corrections above, validate that the install can complete the bootstrap without the network dialog. Use this sequence:

1. Open cmd.exe as Administrator.
2. Confirm:

   ping 127.0.0.1
   ping %COMPUTERNAME%
   nslookup %COMPUTERNAME%
   net view \\127.0.0.1
   sc query FDResPub | findstr STATE
   sc query SSDPSRV | findstr STATE
   reg query "HKLM\SOFTWARE\Microsoft\NET Framework Setup\NDP\v3.5" /v Install

3. All six commands must return success without "General failure" or "service not started" output.
4. Launch Setup.exe as Administrator. The EULA screen should appear within 30 s — if the network dialog returns, capture RASETUP.log and contact Siemens Industry Online Support.
5. After successful installation verify the WinCC project by opening WinCC Explorer and confirming Computer → Properties → Server Name resolves correctly.

10. Troubleshooting Matrix

11. Preventive Best Practices for Future Deployments

• Always pre-stage WinCC 7.2 on a freshly imaged workstation; do not layer it on top of unrelated software.
• Document the static IPv4 address in the engineering station's plant asset register so future technicians do not unplug the cable.
• Keep an offline copy of D:\sources\sxs to enable .NET 3.5 without internet access.
• Disable allow computer to turn off this device to save power on the engineering NIC via Group Policy.
• Snapshot the VM guest immediately after a successful WinCC install so that any future "network not available" dialog can be reverted with one click.
• Schedule periodic review of Windows service states — Group Policy refresh can quietly stop FDResPub on domain-joined workstations.
• When commissioning new PCS 7 stations, validate the SIMATIC Shell visible-station probe before invoking WinCC setup to catch NIC/DNS issues early.

12. When to Escalate

If the network dialog still appears after every check above, escalate to Siemens Support with the following artefacts:

1. The full contents of C:\ProgramData\Siemens\Automation\Logfiles\Setup\.
2. Output of msinfo32 /report C:\msinfo.nfo.
3. Output of netsh int ip reset results (before and after).
4. The exact Windows build string from winver.
5. A screenshot of the failing dialog and the Event Viewer → Application tab filtered by Source ".NET Runtime".

Open a support request at the official Siemens Industry Online Support portal — reference the entry ID for WinCC V7.2 setup / Network probe failure. If the deployment is part of a PCS 7 project, also involve the regional Siemens solution partner.