It's often quickest to check the FAQ and the list below for common answers.
• What is my registration code? You can look it up here
• I'm being asked for a login. What do I use? If your web browser asks for a login when you're connected through a NetShade proxy server, enter netshade for the username and your registration code as password. If you're being asked over and over, you may need to reset your keychain.
1) Open the Keychain Access program in /Applications/Utilities
2) Search for "netshade"
3) Delete all keychain items containing the word netshade
4) Quit and reopen your browsers and NetShade