This was posted on Yahoo Ask by David somebody. But a pal just told me ad.doubleclick is a F-Fox add on, so I'm not really sure what course to take. While my signal is so low doubleclick is the final straw to having a usable web access.
The previous discussion about it was too far above my head to action.
Best Answer - Chosen by Voters
You have the "Search Redirect Virus". This virus not only affects your search results, it can also affect any website that follows a redirect routine, which many do. What is even more annoying is the fact that the virus cannot be detected by your conventional anti virus. This is all due to how the virus manages to infect your system.
Instead of infecting your system by installing software or running a process designed to harm your system, which your anti virus can easily detect and remove, the redirect virus manages to infect a system file. This allows it to evade detection by the anti virus whilst at the same time causing those irritating redirects.
The system file in question is the file associated with the handling of redirect requests. Such requests are made all the time, not only by search engines, but by various other websites. Usually you would not notice, however since the virus has infected this system file, it can redirect you to random websites, usually advertisements, such as ad.doubleclick.net. This makes the hacker's money.
The best way to remove this virus would be to use a program called ComboFix. This has worked brilliantly for me in the past and has not let me down. You can get ComboFix here, along with an excellent tutorial that I always use:
http://www.personalcomputerfixes.com/spy…