Troubleshoot SMB error 0x80070035 by checking name resolution, TCP 445, Windows Firewall, SMB service and permissions.
Start with Check name resolution and work through the six diagnostic checks in order.
Record results before changing configuration and validate the original symptom after each controlled change.
Quick checks
Start with the basic checks in this runbook before moving to deeper troubleshooting.
- Confirm the affected service or component is available.
- Check recent configuration or connectivity changes.
- Run the relevant commands and compare the result with the expected state.
Check name resolution
Resolve the server name and confirm it points to the expected address from the affected client.
Test TCP 445
Test TCP 445 before changing SMB settings. A failed port test indicates a network or firewall dependency.
Check Windows Firewall
Review Windows Firewall rules for File and Printer Sharing on the server and client as appropriate.
Check the Server service
Confirm the Server service is running and the expected SMB share exists.
Check share permissions
Review share and NTFS permissions without weakening security as a first response.
Retest the UNC path
Retest the UNC path from the same client and confirm whether the failure is resolved.
Useful commands
Run these checks from an appropriate administrative session and replace example values with your environment.
TCP 445
Test-NetConnection <server> -Port 445SMB service
Get-Service LanmanServerQuick troubleshooting path
Use this sequence to isolate the failing dependency before changing production configuration.
- Check name resolution → Resolve the server name and confirm it points to the expected address from the affected client.
- Test TCP 445 → Test TCP 445 before changing SMB settings. A failed port test indicates a network or firewall dependency.
- Check Windows Firewall → Review Windows Firewall rules for File and Printer Sharing on the server and client as appropriate.
- Check the Server service → Confirm the Server service is running and the expected SMB share exists.
- Check share permissions → Review share and NTFS permissions without weakening security as a first response.
- Retest the UNC path → Retest the UNC path from the same client and confirm whether the failure is resolved.
What good troubleshooting looks like
Good infrastructure troubleshooting is evidence-driven. Capture the original state, test the dependency that can prove or disprove your hypothesis, make the smallest safe change and repeat the original test.
Symptom → hypothesis → direct test → result → controlled change → validation → documentation