Remote Desktop - Show lower resolution on higher resolution desktop

When you open the Remote Desktop Connection app, click Show Options before connecting - on the display tab, select the resolution you want.

Otherwise, you can launch the RDP app from the command line using mstsc /v:RemotePCNameOrIP /H:768 /W:1024

(where /H:xxx is the height and /W:xxx is the width).

Does it still appear in full screen but with a lower resolution?

Because when I change in under the display tab, it just shows a window in a lower resolution but now in full screen, so it ends up the same.

I want to scale up the remote desktop session so that everything appears bigger.

No, I don't know of anyway to do that, if I understand what you're asking for.  Maybe a third party RDP app, but not the included ones.  

(you can always press CTRL+ALT+BREAK to make it fill the screen but it won't change the scale - it just puts a black border around things).

What you should try is to enlarge the font size in the remote session. As this is not natively possible, some smart guy programmed it. Freeware: http://www.michelstevelmans.com/change-text-size-remote-desktop-session/

With 2x client, I can't find the zoom function anywhere?

On iOS and Android it is 'pinch' to zoom. Make your RDP resolution a low, but still scaled to your screen.
Example a Samsung Galaxy Tab 2 10.1 has a resolution of 800 x 1280 if I want to 'increase the button sizes' then reduce the resolution down by corresponding factors (1280/800 = a factor of 1.6) so resolution could be remade as 600 x (600 x 1.6) or 600 x 960.
Then again in iOS and Android double tap to fit the RDP to full screen then pinch to zoom to specific areas.
Hopefully this works well for you in a Windows Tablet.

Feedback on mine, too, if possible, please.

I've just been speaking to X2 support and they don't support Windows 8 tablets. And the zoom function is not supported neither.

McKnife: I've tried to change the font-size, but that does not change the drop-down-menues etc., so that does not help us :(.

Just to make sure, as it normally does indeed change the dropdown-menues' fontsize, too: did you logoff and logon again afterwards? Could be that not all changes are done until you logon again.

I did logoff and logon again afterwards and when that didn't work i tried with a reboot. But that didn't help neither.

I see no solution then without using 3rd-party-software (and I don't know any suitable).
But do you know the magnifier? If you hit the winkey together with +, all gets big. winkey and - takes it back to normal.

Sorry Vestfrost that zooming does not work on a Windows 8 tablet....can you change the resolution of the tablet? Then RDP full screen will be the lowered resolution. (Win 8 tablet minimum resolution is 1366x768 according to Microsoft.)

It's not ready yet