Follow the below steps:
1. Go to Speech settings> set English(UK)
2.Email+Accounts> choose microsoft account> erase server> don't tick on 'email'> click ok
3. Again Open microsoft account> write 'bay-m.hotmai.com'> tick email> click ok
4. wait some moments and see your microsoft accont will update.
5. Now press and hold search key and see cortana will work.