How do I get rid of "recents" finder window?

You can control what a new Finder window shows. Go to Finder menu > Settings and click on General at the top of that window. Then change "New Finder windows show" to what you want (mine, for example, is set to my home (username) folder and only displays top level folder names).

CSan2C wrote:

Thanks, but I apparently had already done that and it was already unchecked. I checked/unchecked it and I still get the super annoying "recents" finder window.

Then boot into Safe Mode according to How to use safe mode on your Mac and test to see if the problem persists. Reboot normally and test again.

NOTE 1: Safe Mode boot can take up to 3 - 5 minutes as it's doing the following; 

• Verifies your startup disk and attempts to repair directory issues, if needed

• Loads only required kernel extensions (prevents 3rd party kernel/extensions from loading)

• Prevents Startup Items and Login Items from opening automatically

• Disables user-installed fonts 

• Deletes font caches, kernel cache, and other system cache files

NOTE 2: if you have a wireless keyboard with rechargeable batteries connect it with its charging cable before booting into Safe Mode. This makes it act as a wired keyboard as will insure a successful boot into Safe Mode.

Hide "Recents" from the Sidebar:

1. Open Finder.
2. Click on "Finder" in the top menu bar.
3. Select "Preferences" (or "Settings" on newer macOS versions).
4. Click on the "Sidebar" tab.
5. Uncheck the box next to "Recents."

This will remove "Recents" from the sidebar, so it won't be readily visible when you open a new Finder window.