Ccleaner does work IMO, clearing cache and temp files are beneficial for two reasons....
First off the more crap your computer and applications have to sort through the more time that can take....
Also another not uncommon area is some cache files can become corrupt like any other file, so an application referencing a corrupt cache file can cause some serious slow downs and application stability problems.
Either way a good
System File Cleanup, removal of unnecessary application, stop application from boot and doing some infection removal would find this beneficial.
On a side note did no one catch this comment...
sir can i discuss about hacking.
No one find the question odd or out of place for the topic?