Registry cleaners

Been using CC Cleaner for a number of years ... seems good to me

Take care when using CC Cleaner

why ? ... please expand

for a defrag ... I use Auslogic ... free and very good.

When I had Vista PC ... the built in defrag was useless ..

With great power comes great responsibility.

CC Cleaner is very powerful, and in the wrong hands can totally foul up your computer, while in the right hands, it can cure all sorts of problems.

As befits its origins and intended user base, there are no safeguards to stop you doing stupid things.

..the joys of an OS that never needs defragging..

Like xp, vista, win7, win8 then. They never need defragging either. However they can be defragged which will improve disk accesses. Shame linux can't do the same so easily.

All I can add is that have used it for many years .. on many different PC's (& OS variants) and never had a problem ... maybe I have been lucky :-)

I always take the offered step of a backup to registry ... but never needed it, found it to be pretty bombproof.

.. the joys of an SSD that never needs defragging..

I manually delete some stuff from the registry after uninstalling products, but I have a good understanding of what the different types of value are for.

One good reason to delete some things is that some products' installers will not overwrite old keys containing that product's old settings, if you have them, but would put significantly different definitions in place if you do not have them... so to get a proper reinstall you need to remove the old stuff. Also not every uninstaller is sufficiently well-written to get rid of stuff which you might regard as user-set. Some will ask if you want it retained (eg if you want to do an uninstall followed by reinstall and have the new app see the old app's settings).