Autorun.inf files should only -- ever -- be found on a CD-ROM. You should not have ***any*** autorun files in your C:\ root folder, they usually get there because of installing some appplication wrongly, or more worryingly, because of a virus.
You should definitely delete these autorun.inf files. If they come back, this is a sign you have a virus. You should then take the normal steps to deal with this.