Windows Font Weirdness

I left my hand on on shift key too long on my windows box and trigger some kind of accessibility :scare: feature :/scare: . I tried to turn it off and since then, my fonts have been whacky – the text in the titlebars is larger and the kerning is all squished, and the actual titlebars are shorter than before. This has bled into the bold font for unread items in Thunderbird as well – most annoying.

How do I fix it?