Windows – Desktop icons rearrange after using remote desktop connection

1) VNC and RDP are two very different protocols despite being used for similar purposes.

With VNC, the remote system is basically sending you the pre-rendered output of the remote system's video card at whatever resolution it is currently running at. With RDP, the remote system is simply sending over logical information about what needs to be drawn on the screen. Your system then renders that information using the local video card at whatever resolution your RDP client has connected with.

2) Depending on your VNC client, there might be options to shrink the remote display so it fits in your current resolution. Your other option is to actually change the remote system's resolution to match your local resolution for the duration of your connection.

This is probably caused by the fact that the RDP protocol does DPI redirection. If you login (initially) from a machine with a normal display (e.g.: 96dpi), then you connect from a laptop that has a high DPI without logging out (e.g.: any 1080p 13" laptop that sports 120dpi), then everything will look tiny as the session will use the DPI settings that were set in the beginning.

The fix is to log in from the new computer, save and close all programs, open cmd (Win + R -> cmd) and type logoff. Wait for 1-2 minutes, then connect again. This time, all the apps and fonts should be rendered at the right resolution.