Starting next year, Microsoft will be stricter on toolbars and other software that make changes to a browser without the explicit permission of the user. This includes applications that limit users in the choice of search engines or that mislead users in tricking them to change their default search engine or homepage.
The company will also be more strict on software that tries to circumvent the browser confirmation dialog which is allows users to allow or deny installation of a e.g. toolbar. Some applications circumvent this dialog and Microsoft will no longer allow this.
Also software that tries to circumvent or suppress built in security warning of a browser will be blocked by Microsoft’s security software. Previously the software giant already announced it would block software that disables add-on management and proxy servers.