A long while ago I wrote a post about interviewing at Microsoft. Not much has really changed since then, although we don’t ask those puzzle questions any more. So no need to brush up on your taxonomy of manhole covers but do expect to show that you can think logically.
Interview loops at Microsoft are still hard and this puts some potential candidates off. Ask yourself this. If you interviewed somewhere and you thought the interview was really easy, would you still want to work there? You may be smart but will you end up on a team of people who skated through the interview?