How to turn off "SimpleGuideSearchDaemon" pop-up on my iMac?

Please read About those "<app> will damage your computer" messages - Apple Community.

Review the link above provided by John Galt and post a screen shot of these folder:

/Library/LaunchDaemons

/Library/LaunchAgents

~/Library/LaunchAgents

The link explains how to display the contents of those folders and you can post the screenshot of each of them here.

The problem is that you have a file/files in one or more of those 3 locations that is causing the problem. Without knowing what files you have in there, we can help you with what files to remove to eliminate the problem you are having. This same problem has been seen many times here on these forums and the solution depends on the files in those locations.

Files that are installed in those locations can come from a website where a program was downloaded or one of the many Cleaner Apps that claim to clean your system, but only cause problems like you are seeing. The fake Flash Player update dialog is another source of the problem.

Kittersense please restart your Mac in "Safe Mode": Use safe mode on your Mac - Apple Support.

While in that mode, drag all the files in those three folders to the Trash, except those with the following in their names:

Adobe

Amazon

Apple

Brother

Dropbox

Google

Microsoft

Zoom

Those are all ok. You don't need the Brother file any more since it no longer does anything. You can delete it too if you wish. It's not related to the problem at hand though.

Then, restart your Mac normally and confirm the alert messages no longer appear.

Nothing there would be causing the problem. Restart your computer and post a screenshot of the message if it comes up again.

Follow the instructions provided by John Galt and post the screen shots of those 3 folder contents here.

DanCress1 wrote:

Your response was not very helpful. I have already read that.

I don't believe you did.

I have followed the excellent post by John Galt. I still get warnings. Here are the three locations/files. Which files do I delete? Thank you!

I got rid of a bunch of files, but the warning msg still comes up. Where do I look next? 3 Screenshots follow. Thanks for your help; I would never have gotten this far without it.