Users mostly don't know how to get rid of the toolbars.

Multiple toolbars get 'normal' and require a lot of space inside the browser.

Annoying ads are displayed, search results are manipulated.

A lot of these toolbars are annoying for the user: Tracking data is being sent to some backend servers. However, in general they are used to analyze the user preferences and behavior and send this data to other vendors where it's used to present user specific ads. Some of these toolbars claim to be somehow useful. In most cases a Browser add-on (a so called toolbar) is installed. Nowadays almost any free software for Windows comes with some more or less unwanted add-ons which are mostly the cash cow for the product vendor.

Probably you need to restart your Internet Browser, however.

This will re-enable the add-on and all functionality is back.

You can undo this action just by clicking 'Enable'. Disable just switches off the functionality of the add-ons. For this reason avast! Browser Cleanup also offers a button 'Disable'. However, removing an add-on sometimes might not be desired always as you might not be sure what's really behind this add-on. 'Remove' means here uninstall and remove the toolbar and all its components completely from your computer.

What is avast browser cleanup