whenever i accidentally mistype a URL or i go to a bad link, instead of getting the good ol’ 404 message, i get sent to some page from “shopnav.com” with a vaguely related but completely unhelpfull websearch. i went to the shopnav homepage and used their uninstall option but its still happening. is this spyware, and if so, is there any way to remove it?
It’s a search hijacker. Here is information, complete with removal instructions
http://www.doxdesk.com/parasite/ShopNav.html
If you are not comfortable working with the registry, etc., I suggest you download AdAware and/or Spybot Search and Destroy and let them do it.