Totally new-totally confused....

Dear wonderful "computer-literate people:" Please take pity upon me as I am someone who is getting old and I get very confused easily by computers. My question is as follows: I have had this computer (windows 7 laptop, refurbished Acer) since 2009. When I got it, my friend downloaded CCleaner and told me to use it. I use it and the registry button about twice a month or so. Today I clicked on something that said it would return the list to the "default" list and I found out that I have been using it without two boxes being clicked.

One is MacAfee Anti-virus (which I buy) and Windows Media Player which I am constantly using to download music and radio shows, etc. When I ran the cleaner under "analyze" it was going for maybe a half an hour!! It had collected a bunch of stuff that said "MacAfee" and over 10 thousand thingies that said Media player!! I was so afraid that I came here instead of hitting the "clean" button. I know the website says that it only erases junk and clutter, but is it possible that it was going to erase a bunch of music instead? I go to YouTube every day to look at videos so ... maybe that creates "clutter?" I did spend a lot of time rearranging my music and making new folders and categories for it so.... does that create useless "junk?"

Also..... is it bad to erase stuff that says "MacAfee??" I only ask because with the basic package, MacAfee gives me a "quick clean" button which I use regularly. (Then I usually go to CCleaner and it takes away more stuff than "quick clean" did, so I'm used to that.) How come MacAfee doesn't clean itself?? If they didn't want to throw stuff away.... maybe I should unclick that box. I'd hate to mess around with something that is supposed to protect me from viruses.

I don't know why these two weren't clicked before when I first downloaded CCleaner, but perhaps the friend that downloaded it took them off the default list (I can't get in touch with him anymore, though). Anyway.... I'm sure these are probably simple, easy questions and I am being paranoid for nothing. It would be nice if my computer got faster and was less filled up because the pie chart picture doesn't look so good! My computer is definitely stuffed with hundreds of hours of music and talking, but hardly any written pages and "documents."

I'm also probably being paranoid because my sister bought me one of those separate boxes to do "back-up" so even if Ccleaner threw away music files... they should all be on the box (which also filled up remarkably fast considering it was supposed to have a lot of room on it.) Perhaps the files on my back-up-box are also full of "clutter." If some brave, kind younger person could help me I would much appreciate it. I'm still much more accustomed to dinosaur technology like records.... vcr tapes.... click-clacks... Thanking you in advance, chuckle.

McAfee's cleaner inside of CCleaner only cleans logs, they're quite safe to delete :)

As for the Windows Media Player, it deletes a few things

it clears your Recent Files list, you recent URLS list (if you use the net inside of WMP), your last played files list, your radio's Recent Played list, your last played file (not the music file, just the file that points to the last file you played)

Additionally, and I think most importantly for your use case, it’ll delete the Art Cache and the Transcoded Files Cache. I’m assuming both of these are safe to remove with no issues, but truth be told I have no experience with WMP.

Perhaps someone else can shed some light on those last two :)