I am a technician. the keys online you can search are not accepted by ms. they may not work after 3 months. Someone recommended me this site digicalls.com, and, truly speaking, the price attracted me at the first sight, but i am quite suspicious to the site. Then i asked some professional questions to their service team. i was satisfied with their reply. I dicided to buy one. after careful test, the key they provided did work and support all the updates. it's trustable. How can I find out if it's legit? can someone recommend a place with similar prices that you can vouch for?