I just tried to install CentOS (x86_64 4.4 and i386 4.3, not both at once, when I found the 64bit version didn't boot, I tried the 32bit version, same result) on a dual Naconda Xeon system. I get an OOPS just after the IDE info is printed on the screen during boot (this is booting off the CD during the install phase). After mucking about with the bios settings (and many reboots later), I found with Hyperthreading off it boots and installs ok (installed the x86_64 version once I got it going). After YUM updating, and getting a new kernel I thought I'd try turning the Hyperthreading back on, crashed in the same spot during boot. Since I'm going to use it as a MySQL server and Hyperthreading seems to make MySQL slower, it not a problem that it won't work with Hyperthreading enabled, but it would be interesting to know why. Any ideas??? Its a ASUS NCL-DS with Dual 3.4G Xeons, 8G of DDR2 ram, and a 3ware raid controller 8500LP. Regards Mark Strong This e-mail message is for the sole use of the intended recipient(s) and may contain confidential and privileged information of Transaction Network Services. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message.