What's the difference between Certified (Pre-Installed) and Certified?

Created by Jeff Lane 

You will notice in the hardware certification listings at http://www.ubuntu.com/certification that there are two types of certifications. One is "Certified (Pre-Installed only)" and the other is "Certified"

First, Certified means that a system has been tested using the listed non-modified version of Ubuntu. So a system that is listed as Certified for 11.10 and 12.04LTS was tested using the same version of Ubuntu 11.10 and Ubuntu 12.04 LTS that were released to the community and can be found on our website and at http://releases.ubuntu.com

Certified (Pre-Installed only) means that a system was tested using the exact same testing tools, however the OS may have been modified to fix issues that are commonly found when putting Linux on brand new hardware. These certifications work a little differently, and ONLY apply to the custom Ubuntu ISO image that was provided to the OEM for pre-installation on computer systems that are sold around the world.

In a nutshell, it works like this:

The OEM sends Canonical a new system.
Canonical then works on the system and gets it running to an accepted level with Ubuntu. This could mean custom drivers, kernel patches or other work.
Canonical then gives the OEM a custom ISO image that is used to pre-install Ubuntu onto these new systems.

Unfortunately, Canonical does not control where these systems are sold. The OEM decides when and where the systems with Ubuntu pre-installed are sold, so if you haven't seen any on your OEM's web page for your region, it's probably not sold there, but sold elsewhere.

Also, at current time, Canonical can not provide those OEM images to the public.

The goal is to get all fixes that make these custom ISOs work into stock Ubuntu via the normal Ubuntu development cycle. Whether a fix makes it into the next Ubuntu release or two releases from now is entirely dependent on when that fix is finally created, where in the current release cycle we are and whether that fix breaks other things in the new development release. Thus, it can take a while, though many times the fixes DO land in the very next Ubuntu release.