Hello ! TheRemote Desktop on my VISTA 32machine was connection to my 2008 64 bit PDC via Remote Desktop ever since installed and configured in the Firwall correctly, it recently started to fail. <<Remote Desktop cannot connect to the remote computer because the authentication certificate recieved from the remote computer is expired or invalid.>> I first thought there might be a time difference between my PDC and the Workstation, but it is not. Can anybody tell me how to configure things to get connection again? Please reply to clemens.liegler@ados.com ... Regards, Clemens

Hi Clemens, on the server computer, have you tried this setting: 1. Click start, type sysdm.cpl in start search, and press Enter. 2. Under Remote tab, choose "Allow connections from computers running any versions of Remote Desktop" 3. Click OK. 4. Then, please try again. Meanwhile, can you connect to other computers via RDP?

Hi! Just returned from Boston, MAto Europe ... Thanks for the answer meanwhile. The computer is a PDC, so the 'Allow Connections from Computers running any version of Remote Desktop' isnot selectable. Yes, I can connect to other Servers using RDP without problems. As I say'd the problem occurs suddenly, it did work before. Regards, Clemens

Hi Clemens, thanks for the update. For the current issue, if you have already made sure time was set correctly on both computers, you can also check if time zone is set correctly. Make sure time zone is set correctly, synchronize time on both computers and lets see the result.

Hello! I just did another verification. Settings on PDC and Workstation are identical. Time settings and Regional Settings. I do fear that there is something wrong with the Certification Administration but I see no way to find out how to verify the current status. However the whole story is strange. Connecting the the PDC using Remotely Anywhere over https works fine. Does RA not use the same certification methods?Clemens

Hello! The problem can be solved by deleting the certificate, which had expired, in the Local Computer certificate database in the section Remote Desktopon the PDC. Afterthis, no new certificate is created, however it works now again. I am not totaly sure if this is to be seen as a solution for the problem. I tried hard to create a new certificate, but finally gave up. Maybe someone has experience with this. regards,

I am having the same issue as everyone else. I've confirmed that both domain controllers and the client machine all have the EXACT same time, but I still can't login. There must be another way to fix this.

Hey All, You can treat this error through two ways: 1. Is to issue a valid certificate thats from a trusted root CA trusted by the client machines (which is the recommended action as its more secure). To do this follow the steps below: Issue the required TS certificate from trusted CA, and install it in the local computer store on TS server. Open Terminal services configuration. Right click RDP-tcp then Properties. On General Tab you ll find certificates section click select and choose the certificate you have installed. 2. Is to tell the Terminal service server to not negotiate security layerfor with the RDP clients and make it RDP security layer. To do this follow the steps below: Open Terminal services configuration. Right click RDP-tcp then Properties. On General Tab change security layer from negotiate to RDP security layer. Good luck, Tamer Sherif

This worked for me. The problem was that the BIOS battery is dead so when the machine was created it had a date of October 22, 2002 so the certificate was set to expire in 2004. When the date was properly set to June 2009 the certificate was expired.

I did much the same as Clemens Liegler above, however before I deleted the certificate I exported it ( just in case ) and the certificate error then disapperared. I then Re-imported the same certificate and miraculously it now had another 6 months on it and still worked ! Dont know why, but it got around the problem !

Hello TamerTried your suggestion nr 2 and it solved my problem.Thanks

I received a trusted root CA (GoDaddy) certificate, signed the RemoteApps with it fine but ran into an issue with the Remote Desktop server's certificate and Tamer's suggestion worked great in resolving it. ·Issue the required TS certificate from trusted CA, and install it in the local computer store on TS server. ·Open Terminal services configuration. ·Right click RDP-tcp then Properties. ·On General Tab you’ll find certificates section click select and choose the certificate you have installed. Thanks, Tamer.