brush folder location

When you created your custom brushes or brush tool presets did you save them anywhere?  If you do not they would only be in you users ID Photoshop preferences only.  If your Preferences get reset you could well have lost all your Brushes and Tool Presets.  As well as anything else you have added to Photoshop. Like Actions, custom shapes etc.  Whenever you add something to Photoshop you should also save what you add.  So if you the reset or Photoshop reset your  preferences you can load  what you saved back into Photoshop.   When you Define a custom Brush or shape  or add something you should the use the Preset Manager to save what you added to Photoshop.

Reinstalling Photoshop should not reset your old Photoshop Preferences.  So it you reinstall PS onto a new machine or on the same machime you old user ID PS preferences should still be intact.

However, If your preferences have been reset you may have lost what you added in the past.

Adobe Photoshop's brushes are ine Photoshop's Presets\Brushes

Brushes in your running Photoshop are stored in your Preferences Brushes.psp file

You may save your's in your userid presets\Brushes\ Adobe setup for you  for each Photoshop version you use I do not use these folders

You can save them and load them anywhere you want I save the into my own Photoshop tree and use the for every version of Photoshop  I have installed. On Windows  I use Library Docuements  My Photoshop Brushes  The folder is actually on an external USB3 disk