The call we get from small offices around Currie — the veterinary practice at the top of Lanark Road West, the accountant on Riccarton Mains Road, the physio room out towards Balerno — nearly always starts the same way. Two PCs have shared a folder for years. The receptionist saves a booking, the person in the back room opens it. This morning, one PC cannot see the other. The wi-fi works, they can both browse the web, they can even ping each other. Windows just says the share isn’t there, or asks for a password that used to work and no longer does. It looks like the network is down, but the network is fine. Something quieter has changed.
The reason this deserves its own guide, and not just a call to the internet provider, is that the four things that actually cause it are all sat on the PCs themselves, not the router. Peer file sharing between two Windows machines is a stack of about half a dozen small services and settings that were designed for home use, dressed up for office use, and then quietly re-tightened by Microsoft every couple of Windows updates. When one of those settings flips, sharing breaks — and because the router is innocent, the office IT provider often can’t see it. If you’d rather we just came out and looked, that’s what a home or office visit around Currie is for. Otherwise, this is the exact order we work through it on the bench.
Why the Two PCs Suddenly Stopped Seeing Each Other
A shared folder between two Windows PCs isn’t one thing, it’s a chain: the PC has to be assigned a “Private” network profile so file sharing is even permitted, the SMB protocol has to be enabled at a version both ends understand, the credentials the other PC uses have to match a real account on the sharing PC, and a couple of small background services (Function Discovery Resource Publication, SSDP Discovery, Function Discovery Provider Host) have to be running to advertise the machine on the network browser. Break any one link and Windows will tell you the share isn’t there — but it won’t tell you which link broke.
What has almost always changed between “working” and “not working” is a Windows update. The Windows 11 24H2 rollout in particular tightened several defaults that used to be lenient: new networks are assumed Public, SMB signing is required on more connections, and NTLM auth over SMB is deprecated. On a two-PC office that had been running since a Windows 10 install, any of those can go from “not enforced” to “enforced” overnight, and the share vanishes. This is the same pattern we called out in our wider office software broken after a Windows update guide — on a business PC, Windows changes are almost always what turned Friday-fine into Monday-broken.
1. Check the Network Profile: Private, Not Public
This is the first check every time, and it is the one that catches around a third of the calls. Open Settings → Network & Internet → click your active connection → “Network profile type”. If either PC is set to Public, that PC will not accept incoming SMB connections at all, no matter what else you configure. Public was designed for airports and coffee shops; it hides the machine, blocks file and printer sharing at the firewall, and disables network discovery. A brand-new Windows 11 24H2 install assigns Public to any network it sees for the first time, and a Windows Update that resets a network adapter can silently flip an existing connection back to Public without a prompt.
Set both PCs to Private, then reboot both. Not one — both. The other PC needs to re-poll the network browser to see the newly-visible machine, and a reboot is the cleanest way to force that. If the share reappears at this point, keep going anyway: at least confirm the other three items below, because a Public flip suggests something else in the update sequence also moved and you want to know before it bites you next week.
2. Confirm SMB1 Is Off — and It Should Be
SMB1 (the old file-sharing protocol from the NT era) has been off by default in Windows 11 for years, and Windows 10 disables it after 15 days of not being used. That is a good thing — SMB1 is what let WannaCry propagate through office networks in 2017 — and you should not switch it back on, whatever forum posts tell you. But you should confirm it is off on both PCs, because half-enabled SMB1 combined with a modern SMB3 client is one of the ways “0x80070035 The network path was not found” appears on a network that is fine.
Open PowerShell as administrator and run Get-SmbServerConfiguration | Select EnableSMB1Protocol. On both PCs the answer should be False. If it’s True on the machine hosting the share, that machine is trying to negotiate an old protocol first and confusing modern clients — disable it with Set-SmbServerConfiguration -EnableSMB1Protocol $false and reboot. If your share genuinely does require SMB1 (an old QuickBooks file on a Windows XP-era NAS, a legacy time-and-attendance terminal), the correct fix is not to re-enable SMB1; it is to move that data onto a modern share, and that’s something a proper business IT support plan will schedule rather than paper over.
3. Clear the Cached Credentials in Credential Manager
This is the check nearly every office skips, and it’s the one that produces the most frustrating symptom: Windows keeps asking for a password, you type the right one, and it rejects it anyway. That happens because Windows cached the old password behind the scenes months ago and it’s using the cached version, not the one you just typed. Every password change on the sharing PC (which happens on staff turnover, a scheduled 90-day rotation, a domain policy, or just someone tidying up account settings) leaves the other PC holding a stale credential for the same server name.
Open Control Panel (not Settings) → User Accounts → Credential Manager → Windows Credentials. Look for any entry that names the other PC by name or by IP — something like PC-BACK-OFFICE, 192.168.1.42, or domain:target=SHAREPC. Remove every one of them. When you next open the share, Windows prompts fresh; enter the correct current username and password, tick “Remember my credentials” if it’s an office PC that only that person uses, and the new credential is written cleanly. On a shared reception PC where several people log in, don’t tick Remember; being asked once is worth it to avoid re-caching the same problem in a month.
4. Restart the Function Discovery Services
The Network browser (the “Network” icon in File Explorer that lists other PCs on your network) is populated by three background services: Function Discovery Resource Publication (FDResPub), Function Discovery Provider Host (fdPHost), and SSDP Discovery (SSDPSRV). If any of them are stopped or set to Manual and haven’t started this session, the PC will not appear in the other PC’s Network list — even though it’s reachable by name and by IP. Windows updates and third-party antivirus “hardening” both have a habit of setting these back to Manual, and once they’re Manual they only start on request. On a small office with no one requesting, they never do.
Open services.msc. Find each of those three services. Right-click → Properties → set Startup type to Automatic (Delayed Start), then Start the service. Do the same on the other PC, reboot both, and the Network browser fills in within a minute. If you’d rather not open services.msc yourself, a short remote support session is enough to check and set them without a callout — five minutes on both machines and the shares are visible again.
The Bigger Question: Peer Sharing vs a Proper Small-Office Setup
Peer file sharing between two Windows PCs is a fine setup for a two- or three-person office. It adds no extra kit, it uses the machines already on the desks, and if the four checks above are in place it will run for years. What it isn’t good at is scale, safety, or the situations where the network changes: as soon as you add a third or fourth PC, a laptop that comes in and out with a member of staff, a NAS drive that stores the practice records, or a member of staff whose password expires on a schedule, the “works between two PCs” setup starts producing exactly this call every couple of months.
At that point the honest answer is not more tweaks, it is a small file server or a decent business-grade NAS with proper user accounts — a Synology or QNAP in a locked cupboard, joined to the same workgroup, with a nightly backup off to a second drive. It moves the shared folder off the machine that Doreen on reception also runs the till on, which is a good thing for security and a good thing for reliability. It is one afternoon of work rather than a monthly emergency. This is the sort of migration we scope under a business IT support visit, and it also means the same-day emergencies stop being “the whole office is down until this one PC agrees to share” — a business continuity theme we go into on the office printer keeps disconnecting guide for a Loanhead office.
When It Looks Like Sharing but It’s Actually a Mapped Drive
Occasionally the call sounds like “file sharing is broken” but what’s actually broken is a mapped network drive — the drive letter (S:, X:, whatever) has a red cross on it in File Explorer and either doesn’t reconnect or asks for credentials at every boot. That’s a slightly different failure mode, and the fix is different: it usually comes down to how the drive was mapped in the first place and whether the “Reconnect at sign-in” box actually holds. We wrote up the full pattern in the mapped drive keeps disconnecting guide for an Uphall business — if your symptom is a specific letter dropping rather than the whole share vanishing, start there.
When to Call Us Rather Than Keep Poking
These four checks (profile, SMB, credentials, services) resolve most sharing calls we get from small offices in Currie, Balerno, Juniper Green, and the Livingston side. If you have worked through them and the shares still don’t appear, the fault is usually one of three things: an antivirus suite whose “network protection” module is blocking SMB traffic outright, a router that has been reset and has re-issued the two PCs onto different subnets, or a genuine Windows profile corruption from a partial update — the last of which is a straight software troubleshooting job rather than a network one. All three are things where poking further from the front seat tends to make it worse, not better, and they’re the point at which we’d rather see the boxes in front of us than talk you through it. Booking a same-day office visit for a business that’s down mid-morning is what our schedule is built to absorb, and the checks above are ones you can do yourself in twenty minutes without needing us at all.
For a broader look at the small-business IT patterns we see across Edinburgh and Midlothian, our small-business IT tips guide covers the wider set: update policy, backup, password hygiene, and the point at which peer setups genuinely stop being enough.
Last updated: 18 September 2026