The Ask Toolbar and other applications are increasingly being bundled with programs; most notably freeware. It's usually installed during the installation of a program, and it's easy to miss the step where you can uncheck the Ask Toolbar option.
Ghacks has an article on how to uninstall the Ask Toolbar manually or with the Ask Toolbar Remover and includes a section on troubleshooting.
If you find yourself with an unasked install for this particular toolbar here's how to get rid of it.
Off for now,