// OFFICE FILE SHARING
Windows 11 cannot open a shared folder on a Windows 10 PC
Your new Windows 11 machine can see the older Windows 10 computer on the network but will not open its shared folder, while every other PC in the office gets in without complaint. It is almost never a fault on the old machine. It is what happens when a stricter version of Windows meets a share that was set up in looser times — and it is turning up in offices all over Bournemouth, Poole and Dorset as PCs get replaced one at a time. Rated 4.9 on Google.
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/01 — WHAT CHANGED
Why the new PC is the only one that cannot get in
This is one of the most common calls we get from Dorset offices at the moment, and it almost always follows the same pattern. A new Windows 11 machine arrives to replace an ageing one, everything else on it works, and yet the folder the whole office has shared from an older Windows 10 computer for years simply will not open.
Nothing has gone wrong with the share. What has changed is the machine asking for it. Older Windows was content to fall back to a very relaxed way of connecting when a share did not insist on a proper login — effectively knocking on the door and being waved in without giving a name. Current Windows will not do that. If the Windows 10 PC has never been set up to challenge for a real username and password, the new machine has nothing valid to offer and the connection stops there.
The second half of the problem is who the new PC thinks it is. Most new machines are set up with a Microsoft account, so the name it presents is not a name the old computer has ever heard of. In a small office with no server, every PC keeps its own separate list of users, and a share can only recognise accounts that live on the machine hosting it.
The symptoms are usually one of these: the old computer appears under Network but double-clicking it throws an error, or a login box appears and rejects details you know are correct, or the folder opens from every PC in the office except the newest one.
/02 — THE ADVICE TO SKIP
Why we will not switch SMB1 or guest access back on
Search for this error and the top answers are nearly always the same three: turn SMB1 back on, switch on insecure guest logons, or relax the signing requirement. They are popular because they work instantly. They are also the wrong trade.
SMB1 is the original file-sharing protocol, designed in the 1980s and long since replaced. Turning it on is not a per-folder change: the tick box in Windows Features installs the listening server component alongside the client, and it was that server part ransomware used to jump from machine to machine across office networks. You reopen that door on every computer you enable it on, not only for the folder you were trying to reach.
Insecure guest access cuts both ways. If turning it on makes the folder open, that tells you the share itself is already handing files to any device that can reach it — a visitor’s laptop, a compromised phone on the office Wi-Fi, something plugged into a spare socket in reception — with no record of who did what. And the setting you switch on the new PC tells it to connect to any file server that asks for no identity, with no signing or encryption, which is exactly what a rogue device on the network needs to intercept the traffic or serve up a fake share. Losing that record of who opened, changed or deleted what matters a great deal if you ever have to explain an incident to a client or an insurer.
The honest summary is that these settings make the message go away by removing the check that raised it. If someone has already applied them to get you working, it is worth putting the share on a proper footing and turning them back off — an hour of work, not a rebuild.
/03 — SEE VS OPEN
Work out which of the two faults you actually have
Before changing anything, work out which of two quite different faults you have, because they need different fixes. The quickest way is to type the address by hand rather than browsing to it. Press the Windows key and R together, type \\PCNAME using the old computer’s name, and press Enter. Then try the same thing with its IP address, for example \\192.168.1.20.
- Both give ‘network path not found’ — that is a discovery or name lookup problem. If the IP address opens the share and the name does not, the share itself is healthy and only the name lookup is failing.
- A login box appears and refuses you — that is an accounts and permissions problem, and the next section is the one you want.
Two settings on the new PC are worth checking either way. In Settings, under Network & internet, open the properties of the connection in use and make sure the network profile is Private rather than Public. A newly set up PC, or any PC after a router change, often treats the office network as public, which switches file sharing off by design. In the advanced sharing settings, network discovery and file and printer sharing should be on for the private profile.
That test is deliberately built on typing the address rather than on whether the old computer shows up in the Network window. Do not judge anything by that list. It has been unreliable for years, and plenty of perfectly healthy shares never appear in it.
/04 — THE PROPER FIX
Give the new machine a real account to log in with
The fix that lasts is to give the new machine a real account to log in with on the computer that holds the folder. One thing to plan for first: if password protected sharing is currently switched off on the Windows 10 PC, that is why everyone else gets in without being asked. The moment you turn it on, every one of those machines will start asking for a username and password too. Create an account for each person before you make the change, do it at a quiet time rather than first thing on a Monday, and expect to visit each PC once to enter PCNAME\username and tick the box to remember it.
On the Windows 10 PC:
- Create a local user account with a proper password — ideally one per person rather than a single shared login. Leave password protected sharing switched on.
- Open the folder’s properties and set permissions in both places: the Sharing tab and the Security tab. Windows applies whichever is more restrictive, which is why granting full control on the share alone so often changes nothing.
- Give each account only what it needs. Most people need to read and write in one folder, not full control of the drive.
Then on the Windows 11 machine, connect by typing \\PCNAME\ShareName rather than browsing for it. When the login box appears, enter the username as PCNAME\username — the computer name, a backslash, then the account you just created, because left to itself Windows tends to offer your Microsoft account. Tick the box to remember the details.
If it still refuses, a wrong password may already be cached from an earlier attempt. Open Credential Manager from Control Panel, look under Windows Credentials, remove any saved entry for that computer, then try again. Once it connects reliably you can map it to a drive letter so it returns each morning.
/05 — THE BIGGER PICTURE
What piecemeal PC replacement does to your office files
It is worth stepping back, because this error is usually a symptom of something larger. Replacing computers one at a time is a sensible way to manage cash flow, but it leaves the office files sitting on whichever machine happens to be oldest — and now that Windows 10 support ended in October 2025, that may well be the one no longer receiving security updates, unless it is enrolled in Extended Security Updates, which for home versions runs to October 2026. Worth checking rather than assuming — Windows Update will tell you.
A few honest questions. If that computer failed this afternoon, where is the copy of the files? Does everyone lose access the moment the person at that desk switches it off? Could you say today who has permission to what? A share held together by loose settings tends to fail quietly rather than loudly.
There is no single right answer. Some offices are best served by keeping the shared folder on one computer and doing it properly: a supported version of Windows, real accounts, sensible permissions and a backup somebody has actually tested. Others do better with a small network drive. Plenty of the Dorset businesses we look after have moved the whole lot into Microsoft 365, so files follow people between the office, home and their phone and this class of problem disappears.
What we would not do is choose for you from a web page. It depends on how many people share the files, how large they are, whether anyone works away, and what your business already pays for. That is a conversation, not a form.
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// GOOD QUESTIONS
Frequently asked
Why can all our other computers open the shared folder and only the new Windows 11 PC cannot?
Because the older machines were set up in the same era as the share and were content to connect the loose way it expects. The new PC will not do that. It insists on presenting a real username and password, and unless an account exists on the Windows 10 computer for it to use, it has nothing valid to send. Nothing has broken on the old machine — the new one simply holds a higher standard, and that share was never asked to meet it before.
The forums all say to enable SMB1 or guest access. Will that fix it?
It usually does work, which is exactly why the advice spreads so widely. It works by switching off the check that stopped you, leaving the connection unidentified and unprotected on every machine you apply it to. SMB1 in particular is the protocol ransomware used to spread across office networks, which is why Microsoft removed it. Creating a real account on the Windows 10 PC takes about the same amount of time and leaves you safe afterwards.
Windows keeps asking for a username and password and will not accept mine. What should I type?
Put the computer name in front of the username — PCNAME\username, using the name of the PC that holds the folder. Left to itself, Windows 11 tends to offer your Microsoft account, which the older machine has no record of. The account and password must exist on the computer hosting the share, and that account needs permission on both the Sharing tab and the Security tab of the folder. If it still fails, delete any saved entry for that PC in Credential Manager and try again.
I get error 0x80070035, the network path was not found. Is that the same problem?
Not quite. That message usually means the new PC could not reach the other computer by name at all, rather than being turned away once it got there. Try the IP address instead, for example \\192.168.1.20. If that opens the share, you have a name lookup problem. If it prompts for a login, you are back to the accounts issue. It is also worth checking the network profile is set to Private and that both machines are on the same network rather than one sitting on a guest Wi-Fi.
Do we have to replace the Windows 10 PC to sort this out?
Not in order to fix the error — that is a configuration job and can be done on either machine. It is worth knowing, though, that Windows 10 stopped receiving its normal security updates in October 2025, unless that PC is enrolled in Extended Security Updates, which for home versions runs to October 2026. Check Windows Update rather than assuming. Either way, if that machine holds the whole office’s files, the sharing fault is the smaller of your two problems.
Two versions of Windows, one shared folder
We sort mixed-age office networks properly — real accounts and sensible permissions, not a security setting switched off and forgotten about. Most cases we can handle remotely; where we need the machine, collection is free across Bournemouth, Poole and Dorset. Call 01202 775566.
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