WOW! - My drives are back.
Funny thing, before posting to this forum yesterday, I Googled my problem and was provided a Registry Hack to delete the Upper/Lower filters but I could not find they key that was stated in the article.
The Microsoft fix worked perfectly, deleted both registry entries and rebooted and both the LG & Pioneer drives are now visible AND working.
Thanks for all your help and patience - MUCH APPRECIATED.
Cheers.
Ron...