I need to back up my old computer's files as I'm going to reformat the hard drive due to tons of problems and install a more stable operating system. The computer didn't come with a CD-Recordable drive, so I was thinking about buying an external model. I've never backed up data onto a CD before, so my question is: when you backup data to CD-Rs, do you have to choose all the files you want to backup at one time and then as a group copy them to the CD (up to the CD storage limit, of course), or can you do the files one at a time? I'm wondering if I record one file of data with say, only 10 Megs onto the CD, is that all I can copy onto the CD because it's CD-R? Or can I add several other smaller files later one at a time? Is it like a floppy disk where you can keep adding stuff up to the storage space limit? Or, do I have to lump all the files I want to record into one big folder and then transfer that folder to the CD? Thanks.