Looking for some CD-RWs I could use with my parents’ aged computer, I stumbled across a little-known detail of CD-RWs: The discs available on the market are separated into different speed classes. So far, so boring, but the important thing to know is, higher class CD-RWs are not backwards compatible to lower class discs. This means you cannot burn a 12x-ultra-speed disc using a 4x-normal-speed recorder!

Speed classes are:

• “Normal Speed”/”Low Speed”/”Multi Speed”: 1-4x
• “High Speed”: 4-10x or 4-12x
• “Ultra Speed”: 10-24x
• “Ultra Speed+”: 16-32x

My parents’ Plextor PlexWriter 8/4/32A (PX-W8432T) is a 4x CD-RW recorder and is classified as a “normal speed” device. The attempt to write a “high speed” (or faster) disc only produces ATAPI error code 052700 (“write protected”) and fails.

So, if you plan to use that old CD-RW recorder of yours again, start looking for the correct discs. These aren’t in production for quite some time now and begin to get rare. I managed to find some at eBay.