Your Windows password is correct — and completely irrelevant. A NAS is its own little computer with its own list of users, and it has never heard of you. Once that clicks, every NAS sharing problem gets simpler.
People fight NAS connections for hours using Windows instincts: the same password, the same Properties tabs, the same assumptions. A NAS rewards different instincts. It is a separate machine — Linux inside, its own admin page, its own accounts — and Windows is merely a visitor presenting credentials at its door. This page walks the connection the NAS's way: identity created there, permission granted there, address fixed there — and then shows the three behaviours that differ from a Windows host, so the next difference does not surprise you.
Enter your credentials to connect to: NAS-BACKUP
Access is denied.
The account you need lives on the NAS itself — your Windows password was never going to work here.
A NAS is not a folder on someone's PC. It is a small computer of its own — usually running Linux under the maker's interface — with its own users, its own passwords and its own permissions, which know nothing about your Windows accounts. When Windows connects, the NAS asks: who are you here? An account that exists only on your Windows PC is a stranger to it.
Nearly every NAS connection failure is some version of forgetting this. The fixes below are all the same fix, really: create the identity on the NAS, grant it there, and present exactly that identity from Windows.
Sign in to the NAS admin page (in the browser, at the NAS's IP address). Confirm the SMB/Windows file service is enabled — on Synology it is under Control Panel → File Services → SMB; on QNAP under Control Panel → Network & File Services → Win/Mac/NFS. Then create a user on the NAS with a proper password, and grant that user access to the shared folder in the NAS's own permissions screen.
Use a name and password you choose for the NAS — they do not have to match Windows, and there is a security argument they should not. While you are in the admin page, also note the NAS's exact name and IP address; you will use both.
Open the share by IP first — \\192.168.1.60\Files with the NAS's address — because name resolution for NAS boxes is the flakiest part of home networking. At the credential prompt, qualify the username with the NAS's name: NAS-BACKUP\nasuser. That prefix tells Windows which world's account this is, and stops it offering your Windows identity by default.
Then map the drive and tick Connect using different credentials — this checkbox exists precisely for NAS connections, where the right account is almost always different from your Windows one. Save the credentials in Credential Manager when asked, so the mapped drive reconnects silently.
Permissions are set in the NAS's admin page, not in Windows Properties. The Security tab story from a Windows host does not apply; if access is denied, the answer is in the NAS's user and folder settings. Multiple connections are fussier: the one-identity-per-server rule applies here too — a stray guest session to the NAS can block your real sign-in until you clear it with net use * /delete. Firmware updates reset things: after a NAS updates, shares occasionally need their permissions re-confirmed, and SMB minimum-version settings can jump — a folder that 'broke overnight' after a NAS update is a known pattern, so check the NAS's SMB settings before blaming Windows.
And the speed honesty: a NAS on Wi-Fi, or reached over Wi-Fi, will feel slower than a local drive no matter how healthy the connection is. Judge success by a stable, reconnecting mapped drive — not by local-disk speed.
Everything above leaned on the NAS's IP address, so make that address permanent: set a DHCP reservation for the NAS in your router (or a static IP on the NAS itself). A NAS whose address changes monthly breaks every mapped drive pointing at it, and 'the share died again' becomes a recurring household mystery with a boring, preventable cause. Five minutes in the router ends it forever.
Every check in this guide, shown live on a real Windows 11 PC — the complete network folder fix, step by step.
▶️ Watch Full VideoOnly if you create that same username on the NAS and set a password there — the NAS authenticates against its own list, not Windows'. Matching names and passwords on both sides is a common home convenience and works fine; just remember changing one side means changing the other.
Seeing the NAS is discovery; opening it is authentication and SMB negotiation. Check the credential you are presenting (qualified with the NAS name), confirm the SMB service is enabled on the NAS, and clear any stuck guest session with net use * /delete before reconnecting.
By IP, especially when setting up: it removes name resolution from the list of suspects. Once it works, keep the mapped drive on the IP and make that address permanent with a DHCP reservation in the router.