Virtualbox Resolution 1920x1080 Windows 7

Microsoft docs indicate the error 1618 as ERROR_INSTALL_ALREADY_RUNNING ( Another installation is already in progress. Complete that installation before proceeding with this install.). It is recommended to wait till the current installation completes. Check if there is already an instance of Windows installer running. You can identify this process in Task Manager. Allow the current installation/ process to finish and then try the installation