For Windows 11 file sharing, this usually fails because the PC is not accepting the credentials in the format being used, or the shared folder is not being accessed with the correct account.
Try this on the Lenovo:
- Verify basic network access
- In File Explorer, type
\\ComputerNamefor the Lenovo. - If that does not open, fix network/name resolution first.
- In File Explorer, type
- Make sure sharing is enabled
- Go to Start > Settings > Network & internet.
- Select Status > Network and sharing center.
- Select Change advanced sharing settings.
- Under Private, turn on:
- Network discovery
- File and printer sharing
- Use a local account on the Lenovo for scanning
- Go to Settings > Accounts > Other users.
- Add a local user with a password.
- Avoid PIN-only or passwordless sign-in for this account.
- This is often more reliable for devices such as scanners.
- Share the destination folder explicitly to that account
- Right-click the scan folder.
- Select Give access to > Specific people.
- Add the local account created above.
- Grant the needed access.
- Enter the username in a Windows-recognized format on the Toshiba
- Use
ComputerName\LocalUserName - If needed, also try
.cLocalUserName - Use the password for that local Windows account.
- Use
- If Windows keeps prompting for credentials, store them on the PC
- Open Control Panel > Credential Manager.
- Select Add a Windows credential.
- Enter the Lenovo computer name.
- Enter the user name and password trusted on that PC.
- If the shared printer/file path was previously connected with different credentials, disconnect old mappings first
- Windows does not allow multiple connections to the same server using different usernames at the same time.
- Reconnect using only one account.
If the Toshiba still says the username is invalid, the most likely fix is to use a local Windows account in the format ComputerName\UserName and share the folder directly to that account.
- Fix shared printer connection problems in Windows
- Error message when you try to install a network printer in Windows 7: "0x0000052e"
- The network folder specified is currently mapped using a different user name and password error
- Are there extra steps to set up Other User in Win11 Pro vs Home? - Microsoft Q&A
- Unable to access files across computers that are networked together - Microsoft Q&A