Yes, avg pc tuneup is a commercial program, but it's actually rather worth it if you want your pc fixing, sinse it does a lot of very important tasks for you such as defragging disks (which can save you space, speed things up and! keep your hard drive running smoothly), degragging and cleaning your registry, deleting junk files, optimizing your internet speed, sorting out problems at startup and several other tasks as well.
I've actually noticed my pc runs much faster sinse I bought it and installed it,imho the money was worth it.
I used to use C cleaner myself, but I always found cleaning different bits rather difficult sinse I was never certain which catagory of thing was what, where s avg just makes that easier, pluss does many more jobs besides.
Along with the antivirus it's one of the best utility programs I've found.
With our dreaming and singing, Ceaseless and sorrowless we! The glory about us clinging Of the glorious futures we see,
Our souls with high music ringing; O men! It must ever be
That we dwell in our dreaming and singing, A little apart from ye. (Arthur O'Shaughnessy 1873.)