Office support routed me to windows support who refused to give me service unless I paid for stuff. Went back to the office support guy who was kind of friendly and together we explored some stuff.
What I think happened.
1. New PC. wanted to install office, typed "office" in the start menue. Opened app, clicked link to word and excel, took me to windows store to download office 2016 (first yellow flag since I had a 365 subscription). Installed both, worked fine for an hour.
2. All of a sudden can't open any excel/word/office files.
3. Uninstalled the crap out of office
4. Logged in online to my office subscription and clicked the "install office 365" from online. Installed the entire office suit in one click.
Everything worked...