Look, I really really appreciate people taking the time to offer me advice, but the fact is I only want advice that is going to help me. It's a complete waste of my time to keep coming back to this forum only to read "advice" that is of no use to me. I've said twice I'm on a Mac: if you're not on a Mac as well, and don't actually know the answer to my question, then please don't reply! It's really no help to me whatsoever to know what works or doesn't work on a PC, is it? Macs don't use rsr files as they don't need them; so how do I edit the thumbnail on a Mac?