Microsoft wants smart people. Geeks. People who are passionate about technology. You probably won't be tested on the ins and outs of C++ APIs, but you will be expected to write code on the board.
In a typical interview, you'll show up at Microsoft at some time in the morning and fill out initial paper work.
You will have a short interview with a recruiter who will give you a sample question.
Your recruiter is usually there to prep you, not to grill you on technical quesiotns.
If you get asked some basic technical questions, it may be because your recruiter wants to ease you into the interview so that you're less nervous when the real interview starts.
Definitely Prepare:
"Why do you want to work for Microsoft?"
In this question, Microsofts want to see that you're passionate about technology.
A great answer might be, "I have been using Microsoft software as long as I can remember, and I am really impressed at how Microsoft manages to create a product that is universally excellent."