Remote Desktop: Zoom AND full screen -- how? (Win10 remote, Win7, 2008 & 2003 hosts)
I must say, this has been very frustrating. The Microsoft RDP client is simply missing functionality that is required in this new, multi-DPI world ....
I found a solution, and have verified it both on the Surface 4 Pro and ASUS PB279Q 27" 4K/ UHD 3840x2160 monitors at full DPI, and the Dell XPS 13 (running UltraSharp™ QHD+ resolution (3200x1800)!) -- I expect this approach will work for any high DPI remote.
Further, I have verified it when the host machine is "regular" DPI and high DPI (specifically ASUS PB279Q 27" 4K/ UHD 3840x2160 at native resolution).
First, I should note that the Microsoft remote connection manager path (mentioned here) did not work for me. If it works at all, it would appear that only v2.2 of that tool can do what is needed. The version current at this writing is 2.7, and it did not cut it, despite a lot of tinkering. (But I repeat, the stock remote desktop client should solve for this....)
I found no working solution on any thread here on Stack Exchange. But then I found this thread on the Microsoft forums. It mentions an RDP client I had never heard of: mRemoteNG I tried it, and BINGO.
The Working Solution
mRemoteNG works %100. Just like magic. I get an RDP client, full screen, with alt-tab and other keys passed to the host (just like in the Microsoft RDP client, mstsc.exe), and it looks great. It handles the difference in resolution automagically, and just works!
I have hours of use with it, and it flies. This is the first time since getting this new Surface 4 Pro that I have had usable remote desktop.
So I am happy!
Additional Solution (well, band aid) in updated Windows 10 (June 2016)
The remote desktop client, in updated Windows 10, has a Zoom option in the system menu that works at least with Win2008-R2 and higher target machines. The rendered quality is lacking, but this option does work. (Was very useful after upgrading desktop to high DPI displays.)
This client does NOT remember the zoom level, however, so you find yourself having to set it every time you connect (yuck). This path is a band aid, not a solution.
Reported Additional Solution
Not tested by this writer, but reported by friend at Microsoft: Remote Desktop Connection Manager (https://www.microsoft.com/en-us/download/details.aspx?id=44989)
Windows 7 (or Server 2008) does not support RDP protocol version 8 which introduces DPI remoting (which is what the article you referenced talks about). This results in the behavior that you are seeing - you can have either full screen or zoom, but not together :(
The fix is to update to Windows 7 SP1 (or Server 2008R2 on the server side) and make sure that you have the following patch installed: https://support.microsoft.com/en-us/kb/2923545 - then you will have DPI remoting (so not everything will be tiny).
After you have DPI remoting, if you connect to an existing session (log in as someone who was already logged in), you might run into issues with the Windows UI and applications still have the old DPI settings. These issues have been mostly addressed in Windows 10 (UI elements now scale with DPI settings change). The best remoting experience is Windows 10 to Windows 10.