Did the pop-up happen towards the end of the Arduino SAMD Boards installation process? If so that was the confirmation for installing the drivers for the SAMD boards.
If you are able to upload to your SAMD board without problems then the driver installation is not needed.
If you find that the board is not recognized then you will need to install it. You can do that manually by running the batch file named post_install.bat that is located in the Arduino SAMD Boards platform installation folder (something like C:\Users\<user name>\AppData\Local\Arduino15\packages\arduino\hardware\samd\1.8.11\post_install.bat)