Solved [Solution Given] Changing my client size?

Hey guys!

I have a weird problem. I played for a week on a decent size client, was perfect. Today, I accidently clicked alt+enter, and it went full screen. Immediately after that I clicked alt+enter again and it went to a SUPER small sized client, as you can see here ->() while having a windows-side pop up that said something to the lines of "we've changed the compatibility of your game" or whatever, and I can't seem to change it back to what it was.

Stuff I already did and it didn't help: Restart my computer, uninstall and reinstall(I used the same installer) and playing with properties(couldn't actually do something).

Thank you very much for your help.

 

You're a hero. It worked! thank you very much!