Question: I have a CD that was started in a 'multi-session' format, about 10 years ago, using CD writing software that I no longer have, on hardware that is long gone. The disk has files on it that are otherwise unavailable, but my current setup doesn't understand the particular non-finalized format of the disk. Does anyone here know of any utilities that can read this sort of disk?

the gory details: the disk was written with something called 'adaptec', that came pre-installed on what was probably a windows 95 or possibly windows 98 packard-bell, definitely pre-DVD era. I'm currently at windows XP SP3, but if someone says windows 7 can do it natively, that'll be a good excuse to upgrade.

Answer: 
Old thread - but go to EBAY and buy a copy of Roxio Easy CD Creator 5 (or newer) starting around $5.99.

This SHOULD read the data in direct CD mode and allow you to finalize the CD for future use, but no guarantees.

Worked great for me!!

Otherwise CD recovery toolbox did not work for me. 
ISOBUSTER and CD ROLLER both read the disk but cost $39.99. 
I couldn't get ISOBUSTER to bend on the price, even though I only needed it for one old CD.
Problem I had was someone burned files on a CD and didn't finalize the CD to read on other systems.
Without using the CD on the original computer that burned it, I managed to do it with a program called "PowerISO" (not knowing what software or OS version that created the CD). 

1. Insert the CD
2. Start PowerISO and tell it to open the CD
3. extract the data to a local folder (not another CD)
4. confirm the data, then burn it to another CD (if necessary)

This was done on a CD burned (& not finalized) dated 2/2/2016