To make system clean, i usually use to do Run/dllcache then shift + delete.
Is it safe to do this.

There is a lot of information about that available. The consensus is NO, it is not a good idea. Look at some of the links in the Google search I linked below for reasons.
More generally, be a bit guarded about ensuring your computer is squeaky clean - often the measures taken make no difference to performance and can make matters worse. Computer caches are there to improve speed. On these boards there are folk seeking help after running registry cleaners, wonder tune-up programs, and deleting files.
There's a lot of truth in the saying "If it ain't broke don't fix it".
Always pop back and let us know the outcome - thanks
