Have you ever wondered why a new computer comes loaded with so much rubbish? The main reason is that the PC manufacturers are actually paid by the software makers to load their trialware on, with virus checkers (e.g. Norton & McAfee) being the main pests that make try their best to get customer's attention, details and in turn hopefully their credit card. For example, when was the last time that you have come across someone with a new PC that came preloaded with software that wasn't trialware, e.g. let's say Microsoft Security Essentials (or another free AV) and OpenOffice (or some other free office package)?
There's an interesting guide over at TechRepublic, which goes into more detail and several ways of dealing with the crapware.
From my experience of helping people with setting up new computers, all manufacturers do this, maybe with the exception of some small locally run PC shops. In my opinion, Lenovo and Acer seem to be the worst over the last couple of years, especially with their resource hogging system utilities.