I am having possible hardware failure problem(s) with one of my PC's which is about 4 years old. I use the PC for installing various Linux Distros when new ones are released. A couple of months ago I started getting an error during the copy to hard drive installation step. The error message said something about my DVD-RW drive having problems (It was suggested to clean the lens.) or the hard drive is having problems. At the time I concluded that the problem was the ~6 year old internal DVD-RW drive and replaced the drive with a new internal DVD-RW drive. The problem went away until a couple of days ago when I started getting basically the same error messages and a few times I get application crashes when the CD/DVD is booting to the Live Desktop. I decided to boot the installation DVD from an External USB 2.0 DVD-RW drive. The same problem occurred during the installation attempt. I am in the process of doing a Full Diagnostics Test (including surface scan) of the Western Digital hard drive with the bootable Western Digital's Diagnostics CD. I burned the Linux Distro CD's/DVD's on another PC. I always verify the MD5Sum after the ISO download, and I always verify the burned media after the burn step (IMGBurn). I use good quality CD's/DVD's (Verbatim). Does anyone have any comments on what should be the next troubleshooting steps? Thanks in Advance.