Dagent cannot be remote installed on clients where a non-default administrator account is being used for the login credentials.
Generic error / invalid login
By default, the administrator windows account is the only account that has full access to the C$ of a computer.
The problem above has been noted when an additional local administrator account is created and then used for login credentials in the Remote Agent Installer. This alternative account does not have access to the C$ and the Remote Agent Installer fails.
When installing the Dagent using the Remote Agent Installer..
1. Use the default administrator account located on the client machine to install the dagent.
2. Permit an alternative local administrator account access to the C$ share.
3. Join the client machine to the domain and use a domain admin account that has permissions over the C$ to install the dagent.