You can disable DPI scaling by doing the following in Windows.
- You need a shortcut link to DesignSpark PCB on the desktop, if you don't have one drag one from the start menu.
- Right click on the shortcut and go to properties.
- Go to the Compatibility Tab.
- Check "Override high DPI scaling behavior"
- Select "System" from the "Scaling performed by" pull down.
- Click on OK to save the setting.
- Now launch the program and the icons should be normal size.
The GUI icons in DesignSpark PCB are currently raster based which do not automatically adjust to high resolution displays. Vector based icons are being examined for a future release which will allow them to return to normal size on 4K or UHD displays.