Microsoft Build 2014 Dev. Conference, starting April 2nd and ending on April 4th. Registration is now open with a opening rumor that Microsoft will unveil the first update to Windows 8.1, aka the Spring 2014 update or Update 1. Registration for the event will set you back $2095 US and opened at 9AM PST today at buildwindows.com. Don’t let the price tag fool you into thinking that it will leave any developers sitting on fence trying to decide if they should spend the doe or not, the event sold out in just one day last year. So if you want to go, you better log in right now and get your credit card out.