How To regenerate Terminal server 2008 certificate

The simplest way :

1. Open mmc.exe (Microsoft Management Console) ->add the add-in - certificates for the computer account and select local computer
2. Navigate to the remote desktop folder -> certificates 
3. Delete the certificate for the name of the server and close the mmc instance
4. Open tsconfig.msc and Select the instance in the main window -> rdp -> tcp 
5. Right click and select properties -> on the window that pops up -> Press default -> O.K
6. On the next connection new certificate will be generated.

This will auto generate new certificate for Remote Desktop Connection