The Issue:
You try to connect to a managed computer but receive an error - "Unable to gain access to the computer"
The Solution:
1. Check if the user which logged in to windows and launched ControlUp, is part of the administrators group on the managed computer
2. If you are using a non-admin user to launch ControlUp, you can go in the Console to settings -> AD Connections and set an administrator user which the Console will use when it tries to connect to your managed computers.
3. It might be a DNS registration issue, please verify the server DNS registration.