My system has a problem with Allegro 17.2. At first all of the text was to small to read and the icons too small to make out even with the Icon setting set to"large" I was able to resolve the issue by editing the properties of Allegro.exe under the tab compatibility, then selecting "Change high DPI settings", then selecting the check box "Override high DPI scaling behavior" with the setting under "Scaling performed by:" set to "System". This definitely solved the problem when I re-opened Allegro, I was very happy!!!
Until, I opened a sub-menu/drop-down. They open so large on my screen that the buttons at the bottom are not accessible and half of the text cannot be seen. This makes the program unusable. I've loaded the latest ISR and I also tried deleting the allegro.geo file but it had no affect. I'm currently at a total loss with deadlines looming... Help!!!
Never, ever have encountered that problem. Sorry. Are you on Windoz 10?
Change the dpi settings back to default (to start) then restart Allegro, with the latest ISR it should recognise if you are using a 4K monitor and adjust icons and toolbars to suit. (Make sure your graphics card drivers are up to date with the vendor as well). If this doesn't help go to Setup - User Preferences - ui - general and adjust the tbriconsize to suit. You can also adjust the menu font size under ui - font - fontsize, both settings will need a tool restart.
Perhaps your windows was installed on a high-resolution screen. Window automatically selects a large font to compensate this.
Check the following registry entries, If they are different then change then to the following values (= default font size)
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Fonts]"MS Sans Serif 8,10,12,14,18,24"="SSERIFE.FON""MS Serif 8,10,12,14,18,24"="SERIFE.FON""Courier 10,12,15"="COURE.FON"
Already tried all of these options...