How to avoid boot menu on startup of macbook air
I tried installing a macos update which failed. If I dont use the alt key it tries to install the update again and fails. If I boot up with the alt key, it boots fine into my previous OS.
How do I eliminate that boot menu so that i can just boot up to my previous OS all the time without having to use the alt key?
MacBook Air 13″, macOS 10.13