I have a load of files in the tmp folder. Can they be deleted w/o harming any of the systems, routines, etc of the computer? Which, if any, of these files needs to be kept? Thanks!

Temp files can certainly be deleted. The only time you need caution is during a software install, as the temp folder is often used to "house" files which need to be accessed after a restart. As well, some files in the temp folder may be "active" (currently in use) so you may not be able to delete them dynamically.

CCleaner does an excellent job of getting rid of junk files and regaining disk space. Once installed, spend a few minutes going through the settings. You can choose which (internet) cookies to keep etc.

ok, thanks!

You're welcome.

Please post back with your results.