Click on the two buttons I have and see that they are clicked through the variables on top. There's not much to do since it's a prototype for Windows 94.
I created this a few months ago because Windows 94 had so many sprites it was hard to manage. To improve the situation, I adapted the hitbox tactic usually used on platformers so that it quickly switches to a costume with just the button to detect the mouse click. To learn more about it, look inside. Inspired by this @griffpatch_tutor project: https://scratch.mit.edu/projects/67727504/