I used a Dell laptop for about four years with (Dell supplied) Roxio (version unknown) for data file backup.
After a hard disc fail, I bought another Dell laptop with Roxio Easy Media 9 installed.

All but one of the data backup discs recovered fine. using Roxio. The exception was a disc which Roxio sees as a "finalised" disc (don't remember ever doing that!) which it "sees" but will not open.

Explorer sees the file as type "RRR" and the entire disc full.

Any ideas how I might recover the data?

The disc itself may be corrupt - but try one of the following programs to see if there is anything recoverable on it

http://www.isobuster.com/
http://www.cdroller.com/

They both have trial versions which will let you know if the disc is readable - to actually recover, you need the full version but you don't need to buy it first to find out if it can actually read the data.

If it's compressed data, you may have a problem in that they won't be able to recover the actual data inside the compressed container

Thank you! tried isobuster first, and it could find all the files first try!
I can take it from there.

Thanks again.

Glad to help - hope it works for you