Try checking the add-ons menu for your browser (probably under the 'Tools' menu or 'Options' menu depending on which browser and version you use)
If Ask is listed in the add-ons, then disable it.
Ask used to be called AskJeeves, and is a search engine which has been going as long as Google. As with other Google competitors, it struggles to gain market share, and has resorted to paying to be included in the installers of some other applications (especially freeware ones)
When installing new software, or updating existing software, watch out for a checkbox that says "Install Ask toolbar" or "Make Ask my default search" and make sure you uncheck it (unless you want Ask to hijack your search sessions)
HTH
