Frequently Asked Questions Below is the answer to your question. If your question is not completely answered, please submit a Customer Support Request (CSR) and a representative will assist you.   Does Pop Up Sentry work with XP SP2? Do I need Pop Up Sentry?   Pop Up Sentry is designed to compliment the built in pop-up blocker in XP Service Pack 2. The Microsoft blocker will only block basic pop-up and pop-under windows, and will not handle all of the Flash and Rich Media ads, and certain types of pop-ups. Pop Up Sentry works flawlessly to compliment the XP SP2 pop-up blocking.