LOS ANGELES (AP) — Microsoft is expanding a program that gives schools the ability to prevent ads from appearing in search results when they use its Bing search engine. The program, launched in a pilot program earlier this year, is now available to all U.S. schools, public or private, from kindergarten through the 12th grade.

The program is meant to create a safer online environment for children, but also promote use of Bing, which trails market leader Google Inc.

Redmond, Wash.-based Microsoft Corp. is also giving away a first-generation Surface tablet computer to schools where community members sign up to use the ad-supported version of Bing outside of the school. Sixty parents and friends who do 30 Bing searches a day could earn their school a Surface in a little over a month.