Windows 10 workgroup machines - how to delete RDP warnings?

Question

Hello,
We are working in a LAN network containing more than 20 computers running Windows 10 OS, in Workgroup.
Where users, need to make RDP connections several times a day to those workgroup machines, and everytime, they get the famous RDP warning:

I would like to know, if there's any means we can remove this warning, because i found a setting in the mstsc advanced options, but it's somehow risky.
I thought if there was a certificate or a root certificate or a private key, for a pc, that users need to connect to using rdp, that can be deployed to all other computers so they can trust the self-signed rdp certificate?

Thank you in advance

Answer 1

Hi,
The warning of server authentication fails is could be chose under advanced option of RDC. But per below article, it could also be modified by commands or scripts:

Navigate to Configure RDSH Server Certificates
https://ryanmangansitblog.com/2013/03/10/configuring-rds-2012-certificates-and-sso/
https://ryanmangansitblog.com/2014/05/20/rds-2012-rdsh-certificate-deployment-script/
Note: The author also confirmed the risk of this change: if you don’t mind the certificate warnings, don’t change the Session host RDP certificates. If you make the change from the default, when DNS names don’t match authentication will fail, meaning that you will not be able to access the session hosts.

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Hope this helps and please help to accept as Answer if the response is useful.

Thanks,
Jenny

Answer 2

@Jenny Yan-MSFT
Thank you for your support,
Unfortunately, we are working in a Workgroup environment, and we do not Windows Server machines.
The operating system used is Windows 10 Pro edition
If at we had AD, we could install AD CS and everything would work fine...
I don't know if you have any proposition?
Thank you in advance

Answer 3

Hi,
Thanks for the update. So in your case, the remote connection is starting from 1 client to another?

If then, please go to remote settings and verify if NLA has been enabled. If yes, testing by uncheck the box, but please note disabling NLA will lower the security level of remote connection.

Another method that worthy to try is the scenario one mentioned in below blog: Export the remote machine’s certificate (no private key needed) and create a GPO that disperses the self-signed certificate from the remote machine to the local machine.

Scenario 1: Regardless if RDS Role has been deployed, no internal PKI (no ADCS), and you’re experiencing certificate warning prompts when establishing RDP connections.
https://techcommunity.microsoft.com/t5/core-infrastructure-and-security/remote-desktop-connection-rdp-certificate-warnings/ba-p/259301

Last but not least, in my test environment, I always keep the NLA setting and ignore the certificate warning.

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Hope this helps and please help to accept as Answer if the response is useful.

Thanks,
Jenny