If you are using a 4K monitor at high resolution the A Viewer for Window the wording on the windows may appear quite small, and A Ruler for Windows may not work right for you if launched using the AR4W control.
To correct for this:
1. With A Viewer for Windows not running...
Right-click on the A Viewer for Windows icon on your desktop, select ‘Properties’, select ‘Compatibility’, click the ‘Change high DPI settings’ button, check the two checkboxes, and select ‘System (Enhanced)’ from the second dropdown box. Leave the first dropdown box set to ‘I signed in to Windows’. Clicked ‘OK’, ‘Apply’, ‘OK’.
2. With A Ruler for Windows not running ...
Right-click on the A Ruler for Windows icon on your desktop, select ‘Properties’, select ‘Compatibility’, click the ‘Change high DPI settings’ button, check the two checkboxes, and select 'I open this program' from the first dropdown box and ‘Application’ from the second dropdown box. Clicked ‘OK’, ‘Apply’, ‘OK’.
You can now run both programs and they should work fine