I suspect that most people around here will tell you that you never needed it in the first place! Registry boosters normally do little more than 'tidying up a few loose ends' (which weren't causing any problems anyway) while risking causing harm to registry entries which shouldn't be tampered with. If anything goes wrong with your registry, Windows has inbuilt tools to fix it.
If you're getting McAfee for free you might as well use it but then, at the end of the year, switch to Microsoft Security Essentials (or make up your own security suite of freebies from different sources).
Summary:
You don't need registry boosters and you don't need to pay for security software. Save your money!
Chris