so today i got a second monitor not new used from a friend. so i have the one he gave me as my main and my old as the secondary but the secondary isn't displaying anything my computer recognizes and i can move my mouse over there (can't see it however) i don't know what to do please help me.
one of theses
http://www.newegg.com/Product/Product.aspx?Item=N82E16822136533
2 of theses
http://www.newegg.com/Product/Product.aspx?Item=N82E16820147164
CPU: Intel Core i5-3570K 3.4GHz Quad-Core Processor
CPU Cooler: Corsair H80 with sp 120 quiet
Storage: Western Digital Caviar Black 1TB
Storage: Corsair Force Series GT 120GB
Operating System: Microsoft Windows 7 Home Premium
Motherboard: Asus Maximus V formula
Graphics card: Evga 670 ftw...