Microsoft said it was making people use Bing so they could get the most out of other search-related features in its products.
Many Cortana users have previously preferred to carry out searches with Google rather than Bing.
Windows users will still be able to install other web browsers and use other search engines outside Cortana, said Ryan Gavin, Microsoft's head of search and Cortana, in the blogpost.
However, he said, Microsoft was adding extras to Edge and Bing that meant it made sense to tie these programs to Cortana instead of other search engines and browsers.
Although Microsoft has had some success getting people to use the Bing search engine, Google still dominates in this market.