How to transfer my itunes library to different PC
I have a new laptop and need to transfer my library to new laptop. My PC is windows vista and new one windows 7. I have an external hard drive I can transfer it to. How do I transfer it all? Bearing in mind I have an iPhone ipad and iPod. How do I transfer my apps contacts etc? When I move all this won't it wipe my devices to sync it to the new computer? If so will I loose my contacts pictures, music videos, podcasts, music, videos, tv shows books etc?
Thanks in advance
Josh
iPad, iOS 7.0.4, ipad is ipad air