The uninstaller removes the program completely except the saved settings. Settings are kept so that you do not have to re-enter them again every time you update or re-install the software.
Settings can be deleted completely by deleting the following registry key:
HKEY_LOCAL_MACHINE\SOFTWARE\Karlis Blumentals\Surfblocker and/or HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Karlis Blumentals\Surfblocker