How do I share a folder between two computers at home?
The built-in way to reach one computer's files from another over your own network — what to switch on, why it usually fails the first time, and when a memory stick or a NAS is the better answer.
- Difficulty
- intermediate
- Time
- 35 min
- Read
- 8 min
- Safety
- caution
Short answer
Both computers need to be on the same network and to consider that network private rather than public — the public setting deliberately hides you from other machines and is the reason this fails for most people. Then share a specific folder from the computer holding the files, decide who can read and who can write, and reach it from the other machine by name. If it still will not appear, browse to it directly by name rather than waiting for it to be discovered.
Two computers in the same house, and moving a folder between them turns into a memory stick, or an email to yourself, or an upload to the cloud and back down again. Every operating system has been able to do this directly for thirty years and it still trips people up, for one reason above all others: modern systems treat every network as hostile until told otherwise, and a computer on a network marked public deliberately makes itself invisible. Once that is fixed the rest is straightforward. This is worth setting up if you regularly move large files, if one machine holds the photo library, or if there is a printer or a scanner attached to one computer that everyone wants to use.
Safety
Step by step
- Decide first whether this is the right tool.For moving a few files once, a USB stick or a cloud folder is quicker to arrange. Sharing earns its place when the same folder is wanted repeatedly, when the files are too large to be worth uploading twice, or when one machine is the household's file store. If the answer is a permanent household file store used by several people and devices, a NAS is the better answer and the catalogue has a guide on it.
- Confirm both machines are on the same network.Same wifi name, or one wired and one wireless on the same router. A guest network will not work — guest networks isolate devices from each other by design, which is their whole purpose. Two routers in the house can also put machines on separate networks that cannot see each other.
- Set the network profile to private on both computers.This is the step that fixes most failures. Windows asks whether a network is public or private when you first join it, and public switches off the discovery traffic that lets computers find each other. Find the current network in the network settings and change its profile to private. Do this only on your own network — public is correct in a cafe or a hotel.
- Turn on file sharing and network discovery.Both live in the advanced network sharing settings and both need to be on for the private profile. Discovery is what makes machines appear in the network view; sharing is what allows a folder to be reached. On a Mac the equivalent is the file sharing option in the sharing settings.
- Share one specific folder, not a drive.Right-click the folder, use the sharing options, and add the people who should reach it. Sharing a whole drive, and particularly the drive Windows is installed on, exposes far more than intended and is the mistake with the largest consequences. A dedicated folder created for the purpose is the tidiest arrangement.
- Decide read or write for each person deliberately.Read means they can open and copy; write means they can change and delete. Give read access unless someone genuinely needs to put files back. This single decision is what stops a shared folder becoming a place where things quietly disappear.
- Require a sign-in.Leave password-protected sharing on, so reaching the folder requires an account and password from the computer hosting it. Turning it off allows anything on the network in, including devices you have forgotten about. Create a separate standard user account on the host machine for sharing if you would rather not hand out your own password.
- Reach it from the other machine by name.If the computer appears in the network view, open it. If it does not, do not wait — type the machine's name into the address bar in the form of two backslashes followed by the name. Discovery is unreliable and slow; going directly by name works when browsing does not, and it is the fastest way to find out whether the share itself is fine.
- Map it as a drive if you will use it often.Mapping gives the shared folder a drive letter so it behaves like an ordinary folder and appears in every program's open and save dialogue. Tick the option to reconnect at sign-in, and be aware of the trade-off: a mapped drive that is unreachable makes File Explorer slow to open, and a mapped drive with write access is fully exposed to anything harmful running on your machine.
- Note what happens when the host computer sleeps.A share exists only while the computer holding it is awake. A laptop that sleeps when the lid closes will vanish from the network mid-copy. If the folder needs to be available all the time, that argues for a machine that stays on, or for a NAS.
Common mistakes
- Sharing an entire drive to save time — It exposes everything on it, including system folders and other people's documents, to every device on the network. Share a folder created for the purpose.
- Turning off password-protected sharing to make it work — It does make it work, by allowing anything on the network in without identifying itself. That includes guests, smart devices and anyone who has ever been given the wifi password.
- Treating a shared folder as a backup — It is one copy of the files on one drive, reachable and writable from another machine. Anything that deletes or encrypts files on your computer reaches it too. A backup has to be separate and, ideally, not permanently connected.
- Giving everyone write access by default — Most people only need to read. Write access is how files get overwritten, moved and deleted by accident, and there is no obvious record of who did it.
If it doesn't work
The other computer does not appear on the network at all
Cause: The network is set to public, or discovery is off — Fix: Change the network profile to private on both machines and turn on network discovery. This is the cause the overwhelming majority of the time.
The computer appears but opening it asks for credentials that are refused
Cause: The account name is not being sent in the form the host expects — Fix: Enter the username as the host computer's name, then a backslash, then the account name. For a Microsoft account, the email address is usually what works. Creating a dedicated local account on the host for sharing removes this problem entirely.
You can reach it one way but not the other
Cause: The settings have only been applied on one machine — Fix: Sharing and discovery are configured per computer. Go through the same steps on the second one.
It worked and then stopped after a router change
Cause: The new network is being treated as a new, public one — Fix: Set the profile to private again. Any change of router, or a factory reset of the existing one, produces this.
Copying is very slow
Cause: Wifi at one or both ends — Fix: Wire whichever machine you can. A shared folder over wifi is limited by the weaker of the two wireless links, and a single cable often multiplies the speed several times over.
A Mac cannot see the Windows share, or the reverse
Cause: Discovery differs between the platforms — Fix: Connect by name or address rather than browsing. On a Mac use the connect-to-server option with smb:// and the machine's name; from Windows use the two-backslash form. Both platforms speak the same underlying protocol and connect reliably when told where to go.
File Explorer has become slow to open since mapping a drive
Cause: It is waiting on a share that is not reachable — Fix: Disconnect the mapping when the host machine is off, or stop mapping and use a shortcut instead. The catalogue's guide on the shell not responding covers this symptom in more detail.
Questions people ask
Is this safe to leave switched on?
On your own home network, with a specific folder shared and a sign-in required, yes. The things that make it unsafe are sharing whole drives, allowing access without a password, and leaving it enabled on networks you do not control. Never turn on sharing while connected to public wifi.
Can I reach my shared folder from outside the house?
Not directly, and you should not try to arrange it by opening ports — file sharing is one of the protocols most heavily scanned and attacked on the internet. Use cloud storage for files you need away from home, or a VPN into your own network if you genuinely need the shares.
Can my phone or tablet reach it?
Yes, with a file manager app that supports network shares, and most do. It is a good way to get at a household photo or video library from the sofa without copying anything.
What about a printer or scanner attached to one computer?
The same settings enable printer sharing, and the host computer has to be awake for it to work. A printer with its own network connection is far less trouble, and the catalogue's printer guides cover setting one up.
Should I just buy a NAS instead?
If several people want the same files, the household has a large photo or video library, or you want the files available whether or not a particular computer is on, then yes — that is exactly the problem a NAS solves. For occasional transfers between two machines, sharing a folder is free and enough.