Why can't Windows 11 see my Synology NAS?
Most often it's Windows 11 24H2's stricter SMB security: it requires SMB signing and blocks unauthenticated guest access by default, so a NAS set up for guest or unsigned access is refused. The fix is on the NAS side — enable SMB signing and connect with a real username and password, not disabling security on Windows.
Last verified July 22, 2026 · 2 official sources checked Updated
A NAS that vanished after a Windows update almost always ran into Windows 11's tightened SMB security, not a broken NAS. Microsoft changed the defaults, and older NAS configurations that relied on loose settings now get refused.
The two most common causes
- SMB signing now required. Windows 11, version 24H2 (Enterprise, Pro and Education) requires both outbound and inbound SMB signing by default. If the NAS doesn't sign, Windows refuses the connection (often
STATUS_INVALID_SIGNATURE). - Guest access blocked. Windows has blocked unauthenticated guest logons by default since Windows 10 1709. A NAS share set to allow guest/anonymous access shows: "You can't access this shared folder because your organization's security policies block unauthenticated guest access."
The secure fix (on the NAS)
- Create a real user account with a password on the Synology and connect with those credentials — don't rely on guest access.
- Enable SMB signing on the NAS (in DSM: Control Panel → File Services → SMB → Advanced) so it meets the Windows 11 requirement.
- Make sure the NAS offers SMB2/SMB3 (not SMB1), and connect using the NAS hostname rather than its IP address.
What not to do
Don't "fix" this by disabling SMB signing or enabling insecure guest logons on Windows — Microsoft warns these expose you to relay and ransomware attacks. The correct fix configures the NAS to meet modern security, not weakening the PC. See the specific 24H2 and guest-access questions for step-by-step detail.
Fix the connection, then protect the data
Once you can reach the NAS again, make sure the storage underneath it is sound — the right drives, healthy and backed up.
Related questions
- Why did Windows 11 24H2 break my NAS connection?
- Why does Windows say my NAS username or password is incorrect?
- Why is my NAS not showing up in File Explorer network?
- What should I do when my Synology volume has crashed?
- Is my data safe if one drive fails in RAID 5?
- How do I fix "Authentication failed because NTLM authentication has been disabled"?
- Why does my NAS say "network path was not found"?
- How do I map a Synology shared folder as a network drive in Windows?
Sources
Every technical claim on this page is checked against manufacturer and standards documentation. Dates are when each source was last reviewed.
- Microsoft Learn — Control SMB signing behavior (updated 2025-09-15) — checked 2026-07-22
- Microsoft Learn — Enable insecure guest logons in SMB2 and SMB3 (2025-08-13) — checked 2026-07-22