To install a new CentOS 5.6 server x64 / i686 we recommend the following steps. 1. Download the required ISOs. You will only need CD1 and CD3.http://centos.mirror.aussiehq.net.au/5.6/isos/x86_64/CentOS-5.6-x86_64-bin-1of8.isohttp://centos.mirror.aussiehq.net.au/5.6/isos/x86_64/CentOS-5.6-x86_64-bin-3of8.isoAll the ISO images are available on http://centos.mirror.aussiehq.net.au/5.6/isos/x86_64/Then during the installation process:2. You can SKIP the testing of the CD media step. This is not required.3. Make the logical selections for language, keyboard layout and timezone.4. Network should be set to a static IP address.5. Partition as required.6. Unselect ALL default software packages. See screenshot, https://img.skitch.com/20110805-dmfraxynjk9jkwp2we6aka5xwb.jpg7. Choose to Customize Now the software packages. See screenshot, https://img.skitch.com/20110805-j7sdd5xecp47pu1ju8nsr3rq53.jpg8. Software packages, select: Base System, Base only. Unselect all others. See screenshot, https://img.skitch.com/20110805-c1i731xfmg6ykas4ih8gwuug36.jpg9. You should see a confirmation of the required media, CD1 and CD3. If not then go back a step. See screenshot, https://img.skitch.com/20110805-d6yke9gur1t8aswbikqxx76rs.jpg10. Continue with the installation. Once the CentOS software has been installed:11. Run software updates, yum update12. Start the Zimbra installation process.