Illustrator's font is different for some reason and hard to read, I need to change it so i can read all the tabs and file names. Like file, edit, options, type, select, effects..... swatches, layers.. every tab is in a different font that is hard to read

Illustrator's tabs are all in a different font that I can read.

I need to know how to change it so I can get back to a steady workflow.

For example..

File, edit, options, type, select,  effects, view, windows, help..... pathfinder, layers, swatches, stroke, and the file name (all the tabs)

are all in a different font, I don't know how it got changed but now it is different.

This is a shared computer so someone might have changes it on accident but I'm not sure.