You might just want to reinstall.... cause no one I know has any issue with search/Cortana (other than being annoyed by Cortana's voice)... I use it all the time and haven't had any issues either...
I'm a tad concerned about Windows Movie Maker being declared "obsolete"... how come?? And will I still be able to use it? I'm now teaching Grade 2/3 and I regularly edit Youtube videos (like Just Dance, and other kiddy videos) with it in order to add my own students.... would prefer not to have to use another program (I know there are plenty of better ones - but for free, Move Maker was pretty darn useful).
Hope MS' replacement program works the same way...
I did reinstall multiple times from different .iso files (all from MS) and I also installed it on different PCs. I'm guessing there is a setting that breaks it because I like to turn a lot of stuff off on a clean install of Windows 10.
That was a known issue in one of the test rollouts. Make sure your not a fast ring insider. If you're on the insider program roll back two generations and remove yourself, then update.
If your not an insider rollback one generation, join the SLOW ring insider updates, and then update.
Looks like you caught a bad update that wasn't intended for you.
Also of note is by default Microsoft shares updates to 10 across computers in the same network. Once you do the above on all your systems you may want to disable the update sharing feature which will download a larger ISO initially and then share bits of the same file across multiple computers. So an error in the initial download may well leak into all other updates on the rest of the network