CD and DVD -RW or +RW technology can be unreliable. The disks are more fragile than regular -R or +R write-once disks, and disks recorded on one PC may not be readable on another. I do not see why you are intent on using them. Since a DVD-RW disk can hold only 4.7 GB, you are not going to be able to store much recovery data on each one, and if you use disk spanning methods, you multiply the chance of an failed restore due to failure of one disk. Personally, I would get an external hard drive and a free disk imaging application like Macrium Reflect.