To be quite honest, I used to use Ccleaner and similar programs to clean my Windows XP..but with Windows 7, I don't see the need. It's still as fast as the day I installed it, so why mess with it if it's working for me, right?
I would take a look in the Secutiry section for AV suggestions, since you uninstalled Norton. I personally use Avast and MSE together. I have Avast set to scan my drive once a week, and I use Malwarebytes' to run a full scan once a week.
If you go to Control Panel > Performance Information and Tools, and click on Advanced Tools in the left pane, you can view all the performance tools that come with Windows 7.