@Firefox1701 - I just found this utility (courtesy of my Computer Active magazine so credit goes to them). There is no need to install it if you download the zip file (which I have done) and then extract all files. See ThisIsMyFile 3.81 Deleting locked or protected files. .

I haven't used it but, if CA say it's OK, then it must be safe to use as long as you are sure the files are safe to delete. i.e. That they are indeed the files that you created and are not part of some program/system etc.