You are typing the password you use every day, and the mount still says no. In almost every case the password is fine - something else about the login is wrong. There are three traps on the Windows side and one on the stored-credential side. Check them in this order.
Network sign-in is more literal than people expect. The NAS presents exactly what you typed to Windows, and Windows checks it against the account password of that PC - not the PIN you unlock the screen with, not a fingerprint, and not last month's password that a saved entry keeps replaying. Once you know which of the four traps you are in, the fix takes about two minutes.
👆 On the Windows-mapping side, a stale Credential Manager entry is the number one cause of a correct password being rejected.
Windows Hello makes daily life password-free: you sign in with a PIN or your face and never type the real password. But the PIN only unlocks that PC, locally. Network logons - including the NAS mount - need the account's actual password.
If you have forgotten it because the PIN has covered for it: on the PC, open Settings → Accounts → Sign-in options → Password and set or change it (Windows asks for the PIN to confirm it is you). Then use that password in the mount wizard.
If the PC signs in with a Microsoft account, the "username" for sharing is the full email address, and the password is the Microsoft account password - not a local password, and again not the PIN. People often create the confusion themselves by entering just the name shown on the sign-in screen. For a purely local account, the plain account name and its password are what the NAS needs.
An account with no password at all can sign in happily at the keyboard, but Windows blocks that account from signing in over the network - a deliberate safety rule that has been there for years. The mount then fails no matter how the share is set. Give the account a password and the same mount works immediately.
Changed your Windows password last month? The NAS keeps presenting the old one it stored, and DSM does not always make the failure obvious. Unmount the folder (File Station → Tools → Unmount) and mount it again with the current password, ticking Mount automatically on startup as before.
For drive mappings that reject a correct DSM password, Windows is usually replaying an old saved login:
192.168.1.20) and Remove itnet use * /delete in Command PromptThe command-line equivalent for removing a saved entry is cmdkey /delete:192.168.1.20. Either way, the point is the same: delete the memory, then let Windows learn the right password once.
Watch the video to see which account name and password the mount wizard expects, typed in live on DSM 7.
▶️ Watch Full VideoBecause they are not presenting the same thing. The working PC has the current password saved; the NAS is using what was typed when the mount was created - often the pre-change password, or the PIN by mistake. Re-create the mount with the account password you use today.
Then it is permissions, not the password: the account is being recognised but is not allowed on the share. On the PC, check both the share permissions and the Security tab for that folder, and make sure that exact account is listed with access.
No - the mount cannot recover or bypass it. Reset the password at the PC itself first (a Microsoft account resets online; a local account needs its reset route), then mount with the new password. Until the PC accepts the password, nothing on the network will.