After a run or two with the Malwarebytes. A run by Ccleaner wouldn't hurt but leave the registry cleaner alone. A sfc/scannow probably wouldn't hurt as you say you sometimes "fix" things that aren't broke. Heheh, I'm guilty of that myself sometimes
. The sfc/scannow will check your system file and attempt to repair any corrupted or missing system files. Just click on the links provided for Ccleaner and the tutorial for running a sfc/scannow. Piriform - Download CCleaner, Defraggler, Recuva, Speccy - Millions of users worldwide! SFC /SCANNOW Command - System File Checker
Not sure you would like Windows 8 but thats a whole different kettle of fish. Windows 7 is an excellent O.S. and with just a little care and maintenance is the best O.S. to ever come down the pike. IMHO of course.
Hope this helps. Let us know and if not we can go from there. Happy computing!