Installing Sierra or High Sierra or Mojave on a Mac? Seeing a message that your installer is damaged? The message is wrong. Here's the fix.
The latest Mac OS is 10.15.4 (Catalina), released Tuesday, March 24th, 2020. A supplemental 10.15.4 update was released Wednesday, April 8th, 2020 addressing a FaceTime bug, an Office 365 sign-in bug, and a lot more. The supplemental update is highly recommended. (Remember that upgrading to Catalina from any other macOS is a big deal, and you should be sure that your apps are ready for it.) See this article for information about compatibility with 10.15.
Text is a big part of working with a Mac. Work with text faster by using a couple of text-selection shortcuts. They work almost everywhere.
Spotify wants to run at startup. Maybe you don't want it to. Turns out it's not obvious how to make it stop. This article tells you how.
Mac Mail app couldn't send or receive. Settings were right, and the account worked on an iPhone. Cleaned with Malwarebytes-- problem solved.
macOS Catalina (10.15) requires 64-bit apps. Here's a quick way to check your apps and get a list of those that are not 64-bit.
Safari stores passwords, if you know where to look! Here's where. This is way easier than resetting a forgotten password. Just look it up.
It's great that you set up a Time Machine backup. But is it working? Find out now. Here are two ways to check.
Here's how to fix the "error -9923" issue (an error occurred when communicating with the scaanner). It takes just a few moments, and it works.