|Norton's a huge resource hog & slows the system. Not only that, it doesn't do a very good job. There's very little reason to pay for ANY software these days. There are tons of open source programs available that work just as good, if not better than the commercial programs, plus they're 100% free! And if the one you're using goes belly-up, simply get another one...there are plenty available. AVG Free has been around for years. There's an AVG Pro version & also a Suite...if you like to spend your money needlessly, you can always purchase one of them.|
Getting back to your main question, if you want to be 100% sure your browsing history can't be recovered, do as Dumbob suggested, "Format the HDD and reinstall everything". Even if you wipe out the browsing history (cookies, temp files, history, etc), it's still contained in the index.dat file & there may even be some clues in the system registry. Also, if you never changed your internet settings, everything you've done for at least the past 20 days is stored. CCleaner will delete just about everything related to your internet browsing (including index.dat) but if you're paranoid, the only safe way would be to totally wipe the HDD by writing zeros to it, then repartitioning, reformating & reinstalling Windows from scratch. It will probably take several hours.