ask.com is NOT on your computer! Web sites are NEVER on your computer.
You are probably victime of Home page and search engine highjacking.
It often appen when you install some applications and don't carefully read the text during the installation process. You blindfully agreed to let the installer change your home page and default search engine.
Hint: ALWAYS decline any and all proposed or "Recomended" accessory, addons or side installs and changes offered during the install of any applications.
Set the home page to the one you want. The exact way depand on the browser you use.
Change the default search engine. Here also, it depend on the browser used.