I will put off doing the registry clean up until I learn more.
Well, at least go ahead and get CCleaner and use it. As previously stated, it's often recommended here because it's known to be a gentle registry cleaner. In other words, it's basically not as aggressive in it's cleaning of the registry and therefore has a very good track record of being safe to use.
And then, if you want to try another registry cleaner, I'll suggest Eusing Free Registry Cleaner, one of the ones on the list in the link Carbon Dudeoxide posted back in his first reply to you. I have it installed on my Win XP computer and have never had problems from using it. Also, the user reviews on the aforementioned link are pretty good.
And, anytime you use any registry cleaner, be sure to backup the registry before executing the cleanup. CCleaner and Eusing Free Registry Cleaner both prompt you to do this when you start them.