According to Reddit, Microsoft laid off all their QA people in November of 2014:
https://www.reddit.com/r/Surface/comments/3s14un/just_a_remi...
https://www.reddit.com/r/Surface/comments/3s14un/just_a_remi...
As far as I can remember from "How Google tests software" , Google doesn't have whole QA division too (other than a elite kinda testers) and testing is integrated to developers job(SDET). This was not true for Microsoft for long time. It would take a lot of time for Microsoft to become on par with Google in testing.
Later, the quality org was merged with engineering, "eliminating" the testers by making them devs. This change happened across the company but not simultaneously.
Disclosure: Microsoft employee, but this has all been reported on. e.g. Ars Technica covered part of this:
http://arstechnica.com/information-technology/2014/08/how-mi...