From: http://www.tomshardware.com/forum/all.html?tag=multiseat

From: http://www.hacking-tutorial.com/tips-and-trick/how-two-users-logging-in-windows-7-or-xp-in-the-same-time-concurrent-session/#sthash.0HWonGkM.o7y1kmTf.dpbs

remote desktop

From: http://www.thinsoftinc.com/product_pc_sharing_betwin_ES64.aspx

BeTwin ES is the software that allows multiple users to simultaneously and independently share 
a personal computer running Windows 8/8.1 (32-bit).