Option-key with VNC Viewer to remote control a Mac from a Windows 7 PC

I use a Mac Mini as Home Entertainment System (no keyboard or mouse connected).

To access the Mac Mini from my Windows 7 PC I use VNC (note the Windows 7 PC has a German keyboard).

My problem is that I can't get the Mac "Option-Key" to work. Googling the internet brought up the following tips (which did not olve the problem):

• switching the keyboard to US
• using KeyRemap 4 for Mac
• Change the VNC Viewer (Ultra VNC, Tight VNC)

So I found the special keys configuration in the Mac system preferences > keyboard > special keys. Here I don't manage to make any settings since the remote keyboard (= VNC connection) is not recognised - the system state is "no keyboard connected".

1. Does anyone know a virtual keyboard I could install?
2. Do you know any alternatives on how I can get the options-key to work (using a VNC-viewer)?

In UltraVNC you can press the Scroll Lock key once. This allows you to press your Windows key and have it act like the Command key on OSX (it's in the same position too).

The answer is here: https://www.realvnc.com/products/vnc/documentation/5.0/misc/keyboard-mapping/

tl;dr Opt key is mapped to AltR on US-PC kb and AltGr on non-US PC kb

If anyone knows, in general, how to access remote mac's option key from any client (say, the iOS VNC.app client, or Andriod's VNC client), plz post as answer to OP's question, tia.

Yes there is a virtual keyboard built into OS X.

System Preferences > Keyboard > Show Keyboard & Character Viewer in Menubar [x]

Then you will see an icon in the menubar, click on that and select 'Open Keyboard...'

I found nearly the same problems with Mac-Mini (late 2012), with Italian keyboard.

I've performed some tests with Event Viewer tool found into KeyRemap4MacBook software, by comparing events with the local keyboard and the VNC connected keyboard. I suggest to use it to find what is happening for keyboard related problems.

I've tried with the native VNC server installed in OS X 10.8.4 Mountain Lion, the one installed in OS X 10.6.8, with VineVNC server (v4.01) and RealVNC server (v5.0.6).

Here my most interesting findings:

• Leave native language keyboard on the remote Mac, but set "US Keyboard" on the local PC.
• Use VineVNC server, because I found this is the only VNC server that generates complete Mac keyboard events. For strange reasons, with TightVNC both the native OSX server and the RealVNC server treats both the Win/Alt keys as Command.
• Use RealVNC or TightVNC (2.7.10 or above see http://www.tightvnc.com/whatsnew.php#2.7.10) clients to have "Option" key enabled: TightVNC prior to 2.7.10 and UltraVNC viewers do not send the "Windows" key (which will be mapped to "Option" mac key).

In my tests the real events that are received by the server are always different from the local events of an attached keyboard. For example there is no distinction between left and right buttons when you are connected with VNC (for every client I've tested). RealVNC client version used is "5.0.5 Windows 64bit" on Windows 7 Professional.

About the "no keyboard connected" error, I've not tried nothing but connecting a keyboard to the MacMini (when I'm remotely connected I need to have a real keyboard connected to the Mac Mini !).