how do I delete .rtf files?

I have 3 entries in my C:\ drive each of which are just a long row of letters
and numbers. When I opened one it had 2 folders: "1033" and "setup", which
in turn open up to pretty big files.
The files are termed .rtf (presumably rich-text-files) and I cannot delete
them. Have tried normal and Safe Mode and SmitFraudfix.
Any suggestions?