Network Discovery on Windows, Explained (Why PCs Disappear and How to Fix It)

The Question Behind Every Network Error

"Why can't this PC see that PC?" Almost every Windows file-sharing problem reduces to that one question. The answer is network discovery — the subsystem that lets a Windows machine find other machines on the same network and advertise itself to them. When it works, computers appear in File Explorer's Network pane. When it doesn't, you get a blank pane, a path-not-found error, or a machine that was there yesterday and is gone today.

This guide explains the mechanism, then routes you to the exact fix for whatever symptom you have.

How Discovery Actually Works

Windows uses several cooperating pieces. Understanding them tells you what to check when one fails.

• Network profile (Private vs Public). Discovery is disabled by default on Public networks. A network silently flipping from Private to Public — common after an update or a reconnect — is the single most frequent cause of "everything disappeared." Many fixes below reduce to "set the profile back to Private."
• Function Discovery services. Two Windows services do the heavy lifting: Function Discovery Provider Host and Function Discovery Resource Publication. If Resource Publication is stopped, your PC stops advertising itself — others cannot see you even though you can see them. This is exactly the symptom behind Event ID 7036 for Function Discovery Resource Publication.
• Name resolution (mDNS / LLMNR / NetBIOS). To reach \\OFFICE-PC, Windows must translate that name to an address. Modern Windows leans on mDNS; legacy fallbacks are being removed. What mDNS is and why it matters for file sharing covers this layer.
• SMB, the transport. Once a machine is found, the actual file access uses SMB. SMB has its own failure modes layered on top of discovery — what SMB is and why it's broken on Windows 11.

When people say "the network is down," usually exactly one of these four is the culprit. The skill is mapping the symptom to the layer.

Why PCs Disappear From the Network

The classic "it worked yesterday" disappearance has a short list of causes, in rough order of frequency:

1. Network profile flipped to Public. Discovery off by policy.
2. Function Discovery Resource Publication stopped (set to Manual, didn't auto-start).
3. A Windows update reset SMB / discovery defaults. Microsoft has been disabling legacy SMB1 and tightening defaults — see why Windows file sharing has gotten worse.
4. Fast Startup left the network stack in a stale state.
5. Credential or password-protected-sharing mismatch.

The full walkthrough with screenshots-level detail lives in computers not showing up in network on Windows 11 and Windows 11 network discovery not working. The conceptual version — network discovery explained: why PCs disappear — is the companion to this page.

The Error Code Map

Every cryptic code corresponds to a specific layer failing. Use this as an index:

Error	What broke	Fix guide
0x80070035	Path/name resolution or share missing	0x80070035
0x80004005	Generic SMB/auth failure	0x80004005
0x80070005	Permission / access denied	0x80070005
0x80070040	Connection dropped mid-session	0x80070040
0x80070043	Share name not found	0x80070043
0x800704cf	Network location can't be reached	0x800704cf
Error 1231	Transport unreachable	Error 1231
System error 67	net use name not found	System error 67
Event ID 4098	Group Policy drive mapping failed	Event ID 4098
Event ID 7036	Discovery service stopped	Event ID 7036

If your symptom isn't a code but a behaviour ("keeps disconnecting", "10 and 11 won't talk"), see file sharing keeps disconnecting and Windows 10 ↔ 11 sharing not working.

The General Repair Sequence

When discovery breaks and you don't yet know which layer, run this order — it resolves the large majority of cases:

1. Confirm the network profile is Private on every machine.
2. Set the discovery services to Automatic and start them: Function Discovery Provider Host, Function Discovery Resource Publication, SSDP Discovery, UPnP Device Host.
3. Re-enable network discovery and file sharing in Advanced sharing settings.
4. Disable Fast Startup (it skips a clean network init).
5. Test name then address: if \\PC-NAME fails but \\192.168.x.x works, it's name resolution, not connectivity.

The complete Windows 11 network settings guide and the small-office networking checklist turn this into a repeatable procedure.

Why This Keeps Happening (and the Structural Fix)

Here is the uncomfortable truth: you can fix discovery perfectly today and a Windows update can undo it next month. The subsystem is a legacy stack that Microsoft is actively tightening for security, and it was never designed for the casual peer-to-peer use most offices need. That is why the error catalogue above exists at all.

The structural fix is to stop depending on the discovery + SMB stack for peer-to-peer transfer. A dedicated LAN transfer app does its own discovery and its own transport, so none of the codes in that table can occur — there is no SMB and no Function Discovery service in the path. That is the core argument in Oxolan vs Windows file sharing and the broader LAN file sharing guide.

Oxolan auto-discovers Windows and Mac machines on the LAN using its own discovery — it doesn't rely on Windows SMB or the Function Discovery services that keep stopping (the installer adds the one firewall rule it needs). It transfers at full speed and keeps working through the updates that reset SMB. Setup is about two minutes per machine.

Get Oxolan for Windows · See pricing

This isn't "never use SMB" — a stable, well-configured file server is fine. It's that peer-to-peer discovery is the part that breaks repeatedly, and that part has a clean alternative.

Frequently Asked Questions

Why does my PC see others but they can't see it? Your machine can resolve and reach others, but it has stopped advertising itself — almost always Function Discovery Resource Publication being stopped, or a Public network profile. See Event ID 7036.

Why does it work by IP address but not by name? That isolates the problem to name resolution (mDNS/LLMNR/NetBIOS), not connectivity or permissions. What mDNS is explains the modern path.

Does disabling Fast Startup really help? Often, yes. Fast Startup resumes from a saved state and can leave the network stack stale, so discovery services don't initialise cleanly. It's a standard step in the discovery fix.

Is there a way to avoid this entirely? Use a transfer method that doesn't rely on Windows network discovery at all. That removes the whole class of problem rather than fixing instances of it.