In fact, I encourage users to have at least one program that cleans temporary Internet files (e.g. history, cache, and cookies). A junk file cleaner isn't needed as much but is good to have, although you should keep in mind even a junk file cleaner can screw up your computer if it is badly coded (e.g. delete a system file thinking it is junk). However, that risk with a junk cleaner is much lower than with a registry cleaner.