How to change the DPI setting within a Remote Desktop session to a computer that is running ...
..Windows 7 or Windows Server 2008 R2:
Microsoft has released a hotfix (KB 2726399) for Windows 7 and Windows Server 2008 R2 which allows you to change the dots per inch (DPI) setting within an connected RDP Session.
This hotfix has to be requested manually!
After the installation of this hotfix please restart your machine!
Windows 8 does support it by default!
1. In the Remote Desktop session just right click on the Desktop and select "Screen resolution". You can also find this setting in the Control Panel -> Appearance and Personalization -> Display
2. Now click on "Make text and other items larger or smaller"
3. Change now for example the DPI setting to 125% or choose a custom text size!
4. Logoff your session! The item size will adapt after the next login!
All users should now experience a 125% scaling