I downloaded the 4 .iso files and burned them as images to 4 cd's. When I put in the first cd the system boots and begins the CentOS install, asking language etc questions, then it asks is remaining data on hard drive, floppy or cd. I choose cd and no matter what I put in it says "CentOS cd 4.0 not found, insert in CD drive and hit ok". What am I doing wrong that it is not recognizing the remaining data on the cd's?