@Alex40ar said in How can I reset to a stock shader?:

I'm using Recalbox 4

First, read this:
https://github.com/recalbox/recalbox-os/wiki/Shaders-configuration-(EN)
I think you can manually edit it directly in the configuration file, following the explanation above.
NOTE: You are using an obsolete version of Recalbox, and the Forum does not support it, the correct thing is that you update to the latest version. For this, you need to do a clean installation. As has already been announced on the forum, soon (there is still no correct date) there will be an update, and unfortunately it will require a clean install again, so you may not want to update now, but understand that obsolete versions are not supported.