Hi all. I suspect this occurred after a recent Windows 10 update. I find the windows keyboard key and the clicking the windows screen icon don't bring up the start menu, cortana etc. The search option in the task abr doesn't work consistently. I DL'd windows start menu diagnostics app which initially reported the tile database was messed up and tried to repair it. The screen was black and I let it run overnight with no apparent change. I stopped it, restarted a few times without improvement. I reran the startmenudiag app and it reported no errors.
Now I'm running Tweaking.com Windows Repair 2018 which I found on this website, I believe a while back. It's been running for some 9 hours and is stuck at "Running Repair Under System Account" and "Repair jobs 2/47" I hesitate to interrupt it, but I have no idea if it's making progress or just stuck.
I researched fixing a tile database problem and some sites suggested creating a new user account but I can't access Settings to create a new account.
Post script: while Windows repair is running, I tried startmenudiag again. It's saying "Resolving Problems" and is running "registering applications".
Thanks in advance for any advice! I consider myself an advanced beginner in troubleshooting. I know enough to make a small problem a big one!