Buy a Dell or similar PC and you don't just get the copy of Windows you paid for: you also get (in the UK) an anti-virus suite, an imaging product, about three attempts to sign you up to an ISP, and goodness knows what else. Dell gets paid to add these offerings, which reduces the amount you pay for a Dell PC, but you are lumbered with the job of removing them.
Jason York got more annoyed about this than most and he's written a Dell De-Crapifier script to remove unwanted trialware. (You also need AutoIT, which is free, to run it.) He's written it in a modular way so that other people can add to it, and adapt it for other brands of PC. He says:
Any non-standard program should be uninstalled. Exceptions are made for the Dell utilities that are needed to maintain the PC and drivers and such. For the annoying Dell Support tool, I did not uninstall it, but I prevented it from running on start up. In general, anything that's part of the operating system that's optional should be left alone. Anything that's freely downloadable should be removed. I don't want to get into any debate as to whether the Google Search bar is useful/annoying or not. The fact is, it's not part of a standard build, and you can easily download it, so it should be removed.
Note: I have not tried it. It's written for an American notebook, not for UK machines. If you use it, it is entirely at your own risk.
Comment: What do you think about pre-installed trialware? How much extra would you be prepared to pay for a PC that didn't have any?
