As a Software Engineer I know how poor CDs are as a long-term storage medium. Many CDs work just fine AS LONG AS THE READING DRIVE IS THE SAME AS THE WRITING DRIVE. If not ... you may be out of luck. Very often backups are needed to recover from a systems crash - or when the user buys new hardware. In both cases relying on one particular drive is not very wise. This is not a joke - simple Google searches confirm this to disbelievers. Also the quality of the cd affects greatly: it's not a big secret that cds costing 50 cents DO NOT hold data as well and as long as cds that cost 5 dollars a piece. Quality costs. I've been using CDs as storage medium and transportation medium since the very first cd-writers came out sooo many years back. Nowadays I use only tape-backups to make REAL backups of my stuff - cds are not reliable enough. Tape backups have saved my arse from 2 disk crashes. As a side note ... businesses almost never back up their items on optical medias for the exact same reason - it's not reliable enough.