Added to the wiki's Tech Support page:
https://wiki.project1999.com/Tech_Su..._Windowed_Mode (there was actually a similar, but not quite the same, issue already on the page, so I added it just below).
However, I wasn't quite sure what you meant by "messed with video modes", so I guessed that you were referring to the full-screen resolution settings in eqclient.ini. If not, could you please correct me?