CCleaner is not the best system junk files and registry cleaning tool, but on balance it has not bad cleaning effect and less negative impacts to system stability. So it is a matter of course that CCleaner has become one of the must-have tools for PC users.
When we are powerless to do anything about a computer plagued by various difficult problems and unable to bear anymore, most often reinstalling Windows seems to be the only and best solution. But in fact, before eventually doing so, we can at least try to use Tweaking.com - Windows Repair to full scan and repair all kinds of system errors, failures. It is likely to play an unexpected effect.
Although the Windows built-in control panel has the software uninstall function, its ability on detecting programs is not comprehensive. So, if you want to uninstall cleanly and thoroughly, you have to draw help from some 3rd part uninstallers, such as Final Uninstaller.