Lost all settings

It helps to understand how this all works.

When you install Photoshop, all the installation files go to the Program Files directory (on Windows; Mac OS works the same way). All of that is read-only and remains unchanged.

Now, the instant you open Photoshop and start using it, the configuration starts changing in all kinds of ways, some obvious, some hidden and under the hood. These changes are all recorded and stored in your system user account. That’s the Settings folder ​@AxelMatt points to, and this is rewritten on every application exit, to capture all changes.

Each major Photoshop version has its own Settings folder! That’s the crucial point that you need to be aware of. The reason for this is that new application code means the preferences (settings) may not mean the same thing. They may be inapplicable altogether, or they may cause problems because of minor differences. So you can’t just reuse them.

In addition, since they are constantly rewritten, preferences are very vulnerable to corruption. Small errors accumulate. Corrupt preferences can cause unpredictable behavior that usually looks like bugs, but that’s not what it is.

Custom actions and brushes aren’t easily re-creatable, so you should always save them out to .atn or .abr files, which you can reload in the new version.

All the rest is pretty easy to set up fresh. Considering that you do this once a year, ten minutes isn’t really unreasonable, and it’s a cheap insurance against problems and instability.

​@TO72  Sorry, but if you don’t have a backup I think you’re out of luck. You have to create your setings manually. If settings are deleted during an update—for whatever reason—they are gone. Nor can they be restored by installing a previous version.

If you make extensive changes, create various actions, and so forth, it is absolutely essential to create a backup. Situations can arise—such as software errors, hardware failures, etc.—in which your settings are lost.

More infos you’ll find here: Migrate presets, actions, and settings

The easiest way to save settings is to copy the following path to a save place like a external hard drive

• Mac: <Username>/Library/Preferences/Adobe Photoshop <version> Settings
• Windows: C:\Users\<username>\AppData\Roaming\Adobe\Adobe Photoshop <version>\Adobe Photoshop <version> Settings

Note: The User Library folder is hidden by default. To access the content in the hidden folders see here:

• MacOS: Access hidden macOS library files
• Windows: Show hidden files, folders, and filename extensions in Windows
   

I've been doing this regularly for years.