The obvious way is to duplicate it to an "image copy" on HD. If the copying app manages to read all the sectors, then it must be OK. For simple ISO9660 CDs, simply copying off the data may be enough. There are also programs (such as CDcheck, http://www.elpros.si/CDCheck/) which will test out your CDs for you. Once, just before the old one goes bad :-) Seriously, I've not actively gone back through my stuff to check, but I have dragged stuff off CD a few years after burning and so far I've only hit one bad CD. And even that one may have been burned badly - these days I do a check against the source when writing a CD. It was that bad CD that made me start doing that! For *important* stuff, consider making two copies. OTOH, five years from now you will be moving your CD-R (and CD) stuff over to whatever the next high capacity media happens to be (C3D, http://www.c-3d.net/tech_frameset.html, with 125*G*B per recordable disk, looks to be adequate ...) CDRWin http://www.goldenhawk.com/ and CloneCD http://www.elby.org/ can both do this and both have free demo versions. There are plenty of others (I just don't remember which have freebie versions). If your CDs have some for of copy protection, then things may not be so straightforward. Tim Shoppa's RT-11 CD is set up this way (IIRC). I don't know how he did it, but it's clearly possible. The trick for this kind of stuff is usually to have the non-ISO9660 filesystem set up to use the bits of the CD not used by the ISO9660 system. For details on how to do this for OpenVMS's ODS-2 see http://www.tmesis.com/cdrom/. If you want to have the ISO9660 and ODS-2 filesystems share (some or all of) the same data (i.e. you want maybe 600MB of data visible to each fs) then see: http://support.tditx.com/~odsiso/index.html. Neither of these do exactly what you want, but they illustrate the general principle. Antonio