Hello there,
I've had this happen to me too, it gets installed along with something else you wanted and downloaded. The easiest way to get rid of it was to uninstall the toolbar from the installed programs. If it asks if you want to keep 'Ask' as the default search engine, click no!
Here is how:
Windows XP:
Close all open Web browsers
From the "Start" menu in Windows, select "Control Panel"
Select "Add/Remove Programs"
Select the program with the Ask logo and the text "Ask Toolbar" (or our partner’s brand for a custom Toolbar)
Click "Change/Remove"
Windows Vista:
Close all open Web browsers
From the "Start" menu in Windows, select "Control Panel". Under the "Programs" icon, select "Uninstall a program"
Select the program with the Ask logo and the text "Ask Toolbar" (or our partner’s brand for a custom Toolbar)
Click "Uninstall" and then "Continue" to remove the Toolbar
Windows 7:
From your computer's 'Start' button, select 'Control Panel'
Click the "Uninstall a Program" option found under the "Programs" category
Select the program with the Ask logo and the text "Ask Toolbar" (or our partner's brand for a custom Toolbar)
Click 'Remove'
You can also uninstall the toolbar directly from the toolbar
Click on the chevron (down arrow) on the Option button on the toolbar
Select "Uninstall" from the drop down menu
Click "Yes" when asked "Are you sure you want to uninstall this product"
Close all open web browsers
Click "OK" on the popup window
If that does not work try the "HijackThis by Trend Micro" it will identified and removed the Ask.com browser helper.
All the best to you, and I hope that this helped you.
Barbara