Hi,
You may try the aqEnvironment.RebootAndContinue() method and check if it works for you.
Another idea is to setup three different VDIs and start them logging-in as required users. Then, if you have enough licenses, you may consider Network Suite to execute actions on the required VDI. If you don't have enough licenses, you will have to create some driver (e.g. batch file) that will start TestComplete on the proper VDI (via WMI, for example), trigger execution of the required action, close TestComplete and continue with the next VDI.
One more possible option, depending on the actual need and implementation, is not to use GUI tests but do required actions (verification, approvement, etc.) via API calls and try to tweak them so that they are executed on behalf of the required users.
Is there a way we can automate the VDI logging and logout using TC ?
Since you said that after that you are on RDP, then the answer is yes, but not all in one piece. RDP is a line that TC can't cross. You can use TC for VDI login but it won't be able to execute anything on the remote machine, and as you've already discovered, you can manually log on to VDI and then use TC that's installed on the remote machine.
You'll need enough licenses to implement AlexKaras 's solution in order to automate both sides with TC.
