CD-RW problems
 

I used a friends computer to back up most of my data on CD-RW. His PC (Sony Laptop) is fairly new and his OS is XP.

I am facing the problem that my old machine (P1, WIN98, Toshiba 12X CD drive) cannot read this CD-RW. Is this hardware-related or can this be solved with a software-patch?

7 7 7 7

It's the CD drive. A very few early x12 drives could read them, about 50% of x16 drives, everything after that is fine. You can pick up a x52 drive for about £30 or less.

It's a hardware problem, an RW doesn't reflect as much light as a R disk and the sensor isn't sensitive enough to detect and read the data, so you can't fix it, only replace it.