Why Is Microsoft resetting my default search engine to Bing without my permission?

Earlier today I was carrying out a search and a window popped up stating that an application outside Google had changed my default search engine. When I checked, all my search engines listed in the Address Bar Search settings had been deleted, and Bing (which I had deleted) had replaced them. As I understand it, this is a breach of the UK Computer Misuse Act as it was carried out without first obtaining my consent to make the changes. Once again, Micr*sl*p is trying to force me to use their rubbish applications.