Signing into a different Active Directory domain on a Windows 10 computer is mostly a matter of typing the account name in the right format on the sign-in screen. Windows uses the domain part of the name to decide which domain controller should check your password, so if you enter it correctly and the computer is allowed to talk to that domain, you can log in with an account that isn’t from the computer’s own domain. This guide covers the name formats, the steps, what needs to be in place first, and how to fix the most common error messages.
Username Formats Windows Accepts
On the Windows 10 sign-in screen, the text you type in the user name box tells Windows where your account lives. These are the formats you can use:
| Format | Example | What it does |
|---|---|---|
| DOMAIN\username | CONTOSO\jsmith | Signs in with an account from the named domain, using its short (NetBIOS) name. |
| username@domain (UPN) | [email protected] | Signs in with the account’s user principal name. Often the easiest choice for a trusted domain. |
| .\username | .\Administrator | Signs in with a local account stored on this computer, not a domain account. |
| COMPUTERNAME\username | PC01\Administrator | Also signs in with a local account, naming the computer explicitly. |
As you type a name with a backslash, Windows shows “Sign in to:” under the password box with the domain it will use. That is a quick way to confirm you’ve typed it right before pressing Enter.
Steps to Sign into Another Domain on Windows 10
- Get to the sign-in screen. Press Ctrl+Alt+Delete, or sign out of the current account first if someone is already logged in.
- Choose Other user. In the lower-left corner, click Other user. If you only see one account, click the arrow or press Ctrl+Alt+Delete again to bring up the option.
- Type the account in domain format. Enter DOMAIN\username or [email protected]. Check the “Sign in to:” line shows the right domain.
- Enter the password. Type the password for that domain account, not the password for the computer’s usual account.
- Press Enter. The first sign-in creates a new profile on the computer, so it can take a minute or two.
What Needs to Be in Place First
Typing the right name only works if the domains and the computer are set up to allow it:
- A trust between the domains. The computer’s own domain must trust the domain your account comes from. Accounts in the same forest usually work automatically. Accounts from a separate forest need an external or forest trust set up by an administrator.
- Permission to log on locally. The “Allow log on locally” right (and, for remote sessions, “Allow log on through Remote Desktop Services”) has to include your account or a group it belongs to. Some companies limit this with Group Policy.
- Network access to a domain controller. The computer must reach a domain controller for your account’s domain. Off-site, that usually means connecting to the company VPN first, or using a VPN option on the sign-in screen if your organization offers one.
- Working DNS. The computer needs DNS servers that can find the other domain’s controllers. If it uses the wrong DNS, Windows can’t locate them.
Common Errors and Fixes
“The user name or password is incorrect”
Check the domain part first. A missing or misspelled domain makes Windows try the account in the wrong place. Also check Caps Lock and the keyboard layout shown on the sign-in screen.
“The trust relationship between this workstation and the primary domain failed”
The computer’s own account in Active Directory is out of sync. A domain administrator can fix it by resetting the computer account, or by signing in with a local account (.\username) and rejoining the computer to the domain.
“There are currently no logon servers available”
Windows can’t reach a domain controller. Check the network cable or Wi-Fi, connect the VPN, and confirm the DNS settings point to your company’s DNS servers.
“The sign-in method you’re trying to use isn’t allowed”
Your account doesn’t have the right to log on to this computer. Ask an administrator to add you to an allowed group or adjust the policy.
Tips
- Run one program as another domain user. If you only need one app, hold Shift, right-click the program, and choose Run as different user. You can stay signed in with your own account.
- Check who you’re signed in as. Open Command Prompt and type
whoami. It shows the domain and user name of the current session. - Use the UPN when in doubt. The [email protected] format avoids confusion when the short domain name differs from the full DNS name.
- Know your local admin. Keep a working local administrator account so you can fix domain problems if domain sign-in fails. Our guide on switching to an administrator account can help.
Related: Remove an Azure AD account from Windows 10.
Frequently Asked Questions
Can I sign into another domain without joining my computer to it?
Yes, if your computer’s domain trusts the other domain. Your computer stays joined to its own domain, and the trust lets it check the other domain’s accounts.
Will my files and settings carry over?
No. Each domain account gets its own profile on the computer, with its own desktop, documents and settings.
Does this work on Windows 10 Home?
No. Windows 10 Home can’t join a domain, so domain sign-in needs Pro, Enterprise or Education.
Is Windows 10 still supported?
Microsoft ended support for Windows 10 in October 2025, so it no longer gets regular security updates unless enrolled in Extended Security Updates. Domain sign-in works the same way on Windows 11.
Summary
To sign into another domain on Windows 10, choose Other user on the sign-in screen and type your account as DOMAIN\username or [email protected]. It works when the domains trust each other, your account is allowed to log on, and the computer can reach a domain controller. If it fails, the error message usually points to the name format, the trust, the network, or logon rights.
Kermit Matthews is a freelance writer based in Philadelphia, Pennsylvania with more than a decade of experience writing technology guides. He has a Bachelor’s and Master’s degree in Computer Science and has spent much of his professional career in IT management.
He specializes in writing content about iPhones, Android devices, Microsoft Office, and many other popular applications and devices.