Did these files come from a CD when you opened them? CD files all have READ ONLY attributes. You can Copy/Paste them, you can Open them. But you can't modify and Save them or Move or Delete them once you put them onto your hard drive unless you change that attribute (Right click the file, Properties, click off Read Only attribute). You Can do a Save As to another name, however. But of course, the original file stays as originally created until that attribute is changes. This is true of all files on a CD, not limited to Illustrator files, of course.