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: 
[IsoBuster](http://www.isobuster.com/), [CDRoller](http://www.cdroller.com/), or [CD Recovery Toolbox Free](http://www.oemailrecovery.com/cd_recovery.html) might be able to read the data back off of that disc. CD Recovery Toolbox Free is, well, freeware, but not as powerful as the other two. IsoBuster has free functionality and Pro functionality that requires registration. If you burned the disc as an open multi-session disc with Easy CD Creator, then the free functionality should be all you need. If you burned the disc with DirectCD, then you'd need the Pro version.

Both Easy CD Creator and DirectCD were Adaptec products.

Finally, there's [Roxio's UDF Reader](http://www.roxio.com/enu/support/udf/software_updates.html) -- that may also allow you to read the disc. Roxio took over the development of Adaptec's CD/DVD burning software several years ago.
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