Updated: August 17, 2016
This article describes the issue when you connect to Windows 7 machines with DameWare Mini Remote Control (DMRC) and you can control the mouse but for some reason, you are unable to use the keyboard at all.
The responses appear to be not sent across to the remote machine
There is a Keyboard driver which gets installed as part of the Dameware suite and is likely disabled or broken (Windows updates or anti-virus).
You need to uninstall all Dameware components from the problem machines and then re-install the DMRC Client Agent