Just a warning to those who use PrivateFirewall. Since the GUI is confusing, I accidently blocked explorer.exe, since I thought it was blocking Internet access (apparently not), and it almost destroyed my entire desktop. All desktop icons and taskbar icons stopped working, and I couldn't even access the PrivateFirewall settings, since itself ran as a taskbar icon. I was able to uninstalll PrivateFirewall, but all of its previous settings remained. I had to search and delete every remaining bit it left behind to get it back to normal again. What a mess.