And in other creepy news... Before I log in on a PC, the ads that show up are for sites or products I've browsed recently. Big brother, and his whole high school football team is watching. Well played, Internet Explorer.
this has nothing to do with IE, this is just how google ads work, it looks at keywords in your search/cookie history and decides what ads to show (for example it may find alot of searches containing the word 'truck' which is why you might see truck ads from various manufacturers, or if might see 'chevy' and some searches containing your zip code, like directions or something, so you might see ads for your local chevy dealers, etc). its not like a key logger thats trying to get your passwords or anything sinister like that, its just trying to show you relavant stuff to you rather than just random things.
however running CCleaner is a good idea, it just cleans the stored up crap out (it was actually originally called 'crap cleaner' before it was purchased by piriform and got a slight namechange). its got a good registry cleaner too, and you can use it to easily disable/enable startup programs as well. not bad for free.