Microsoft could do a much better job managing their vendors who create these sites for them to render well cross-platform and responsively.
This one looks decent on Chrome mobile with the photos going edge to edge with no margin, but the site for the event at http://www.microsoft.com/october2015event/en-us/live-event looks pretty amateur hour on Chrome mobile on my Moto X: huge margins and padding that result in text paragraphs with two words per line.