No you won't be able to access the remote control service (RCS) in WG because you can't log into GateKeeper - which is the GUI for WG's engine.
If you know the Administrator password for GateKeeper/WG then most likely there is a policy (or lack thereof) in the RCS that won't allow anyone, including the Administrator, to log in. This usually happens unintentionally when policies are being adjusted - in your case??? In this situation you can apply a Windows registry fix. You can download it
here, unzip it and double click to install the fix. This fix adjusts the RCS policy to allow Administrator log ins. Before applying the registry fix, stop the WG engine, then apply the registry fix, then restart the WG engine. Wouldn't hurt to backup the registry or create a system restore point before applying the fix either.
Let us know if this helps.