Eve.8ryone, I have had a SuperMicro machine running Centos 5.8 that had been progressively updated with yum-cron from a 5.0 CD install. I upgraded the SuperMicro with more memory, switched out the CD with a DVD and tried to boot to the Centos x64 6.2 dvd. My plan was to test the memory before I added the hard drives, but I could not I could not get the machine to boot from the disc. I also tried some Fedora install discs as well as LiveFedora and the machine would still not boot. I could get it to boot with a dreaded Microsoft install disc. We also updated the bios with the latest version and this did not make a difference. We have not tried to use these disks with the hard drives installed yet because we were in the process of just testing the memory. Has anyone had this problem with SuperMicro's. Is the problem as simple as a requirement to have a hard disc installed. Your help would be appreciated. Thank you, Greg Ennis