Why are my Pop-Up windows smaller?

If the pop up windows suddenly became smaller without you changing the Photoshop interface settings, I would first check your display scaling and resolution.

On Windows, go to Settings > System > Display and check whether the Display resolution or Scale setting changed. A change there can make Photoshop dialogs appear much smaller even though Photoshop itself has not changed.

If Windows scaling is unchanged, check Photoshop under Edit > Preferences > Interface and look at the UI scaling or font settings. After changing anything there, restart Photoshop.

If only specific dialogs such as Expand Selection or Export As are smaller, a screenshot of another affected dialog would help. Some Photoshop dialogs have a fixed size, so the solution can be different from changing the general interface font size.

 ​@DaveMan1000 in addition with ​@LAMY2017 , are you asking about the ‘Expand Selection’ dialog pop-up box? I would be a fixed-size dialog and cannot be resized independently. 

If you are asking about the Interface fonts, go to Photoshop Preferences - Interface and change the Presentation fonts: 

Dave, man, I’d love to help but I’m confused. I can’t reproduce what I see in your posted image. especially ‘expand selection.’

“editing and exporting in Photoshop” (I don’t see the export dialog; I see the Crop tool selected, one layer, marching ants around selected text)

And it’s not a Text box judging by the thumbnail in the Layers panel -- no “T’. So it’s a file?

Screen resolution + Settings = really small?

More hints, please.