Q: If iTunes repeatedly prompts you to authorize your computer

Frustrations with syncing iPhone 4 with a new laptop running W7. Downloaded latest iTunes, and keep on getting error message: "could not be synced because this computer is no longer authorized for purchased items....". Read other posts, and did everything from this Apple support page: If iTunes repeatedly prompts you to authorize your computer - Apple Support

Still doesn't sync.  Suggestions please and thanks.