Unexpected automatic login in the Windows RDP client usually means credentials are being pulled from an unknown storage location, which can pose security risks or complicate troubleshooting. Locating the exact source of these credentials allows you to control access and prevent unauthorized connections.

Check Windows Credential Manager

Step 1: Open the Credential Manager by pressing Windows + R, typing control /name Microsoft.CredentialManager, and pressing Enter. This tool stores web and Windows credentials, including those used by RDP.

Step 2: Select the Windows Credentials tab. Look for entries labeled as TERMSRV/hostname or TERMSRV/IP address. These entries store saved RDP credentials for specific hosts.

Step 3: Expand any relevant entries to view details. If you find the credentials being used, you can remove them by clicking Remove. This forces the RDP client to prompt for credentials on the next connection.

Review Group Policy Settings

Step 1: Press Windows + R, type gpedit.msc, and hit Enter to open the Local Group Policy Editor.

Step 2: Navigate to Computer Configuration > Administrative Templates > System > Credentials Delegation. Check if policies such as Allow delegating saved credentials or Allow delegating saved credentials with NTLM-only server authentication are enabled. These settings can direct the RDP client to use stored credentials automatically.

Step 3: Double-click on each policy to review its settings. If the policy is enabled and lists your target server, consider setting it to Not Configured or Disabled to prevent credential delegation.

Investigate RDP File Configurations

Step 1: If you use .rdp files to connect, open the relevant .rdp file in a text editor such as Notepad. Look for lines like username:s: or password 51:b:.

Step 2: Remove any saved username or password lines to prevent the client from auto-filling credentials. Save the file and reconnect to confirm the change.

Clear Cached Credentials from Windows Security Dialog

Step 1: When connecting via RDP, if the Windows Security dialog appears with a pre-filled username, click More choices and then Use a different account. This allows you to enter new credentials and optionally avoid saving them for future sessions.

Step 2: Uncheck any option labeled Remember me or similar to prevent the client from storing credentials again.

Check for Third-Party Credential Providers

Step 1: Some organizations deploy credential providers or password managers that integrate with Windows authentication. Check for installed software in Control Panel > Programs and Features or by reviewing running processes in Task Manager.

Step 2: If you find such software, consult its documentation or settings to locate and manage stored credentials related to RDP connections.

Tracking down the source of RDP credentials in Windows often starts with Credential Manager but can involve group policies, .rdp files, and third-party tools. Regularly reviewing these locations keeps your system secure and ensures you stay in control of remote access.