If I enter data in this screen

Where are these settings stored. I wanted to blank out these settings ... so I uninstalled SSRS and SSRS SP Add-in. restarted my machine and re-installed the Add-in... but these values remained. (so they survived the uninstall of SSRS and SSRS Addin).
Can you tell me where are these being stored so that I can clean these up? without re-installing OS or re-building the farm I hope.
MSDNStudent Knows not much!