The recruiting process was simple. I've done this twice in consecutive years. Microsoft sent some engineers to my college to find job and internship applicants in September 2013 and again this September.
In September 2013 they had a "mini-interview" round on campus. As I handed in my resume I was asked questions about my experience and interests. A few days later I got an e-mail invitation from a Microsoft HR contractor to do a sit-down interview. The interview happened a couple of weeks later, also on campus, with a Microsoft engineer.
The interviewer was cordial but curt because interviews were 30 minutes and stacked back-to-back all day, with no time cushion between. The interviewers were mostly casually dressed as were the applicants.
My interviewer asked me about my background and experience, then gave me a coding question. All other applicants I talked to were also given a coding problem, not one of those mythical non-tech brain teasers I have read about companies such as Google giving.
I was applying for their no-experience-needed "explorers" internship. I told the interviewer I just started learning about arrays, so he asked me to code an array sorting function. He seemed surprised it was over my head, in spite of it being my first month in intro to C, which Microsoft knew in advance.
I wasn't able to completely code the answer, but the interviewer was helpful, offering general advice on how to complete it. I got a generic rejection e-mail about three weeks later from a do-not-reply address, saying my resume would be kept on file for a year.
This year I got an e-mail from Microsoft again, saying an engineer had reviewed my resume on file from last year and wanted us to do a sit-down interview. It was about the same as last year, though Microsoft was not offering the "explorer" internship anymore, just the need-experience one. My interviewer again was cordial, even friendly, and asked me similar questions to last year, followed by a new coding question that I was given a Surface tablet with an IDE (no compiler) to code with.
I handled it better this year, but I couldn’t finish the code so I talked it out. He asked how to code a translator from a base-10 number system to another system. I had about 15 minutes to code it, with the interviewer at times looking at my screen and notes, and asking questions. He was being helpful but it was too much pressure for me. The interview ended with some advice on how to handle the problem and well-wishes.
I got basically the same rejection e-mail from them as I did last year.
Microsoft has an efficiently structured system for recruiting applicants, processing applications (through web and e-mail) and coordinating interviews. They even use an automated system to remind you of your interview after you select it through a web system. The only weakness is a mismatch between the stated job requirements and what the interviewers expect you to know. In the case of last year's interview, for example, I had to explain what the explorer internship I was applying for was because the interviewer had never heard of it, and seemingly was not prepared to ask questions on that level.