So I got my Nokia Lumia 900 from AT&T, I want to add music and so i download Zune,but when I install it, it says failed to install update,so I get help from a website to update my windows,but i can't,It tells me to restart so i do,but it still doesn't work,also when i connect my usb into my laptop and into my Nokia,I check the devices,and it says that it's unidentifed,but i tried on my sisters laptop and my cousins and it worked,but not on mine,and me and my sister sometimes listen to diffrent songs so she's not willing to download any music for me..Please I really want songs on my phone