I'm guessing you only have one user account in Windows. Windows is different. To have other users, we would have other (windows) user accounts. At least that's how I do that here.
Bob
No doubt this has been covered but I couldn't find where and go easy cause I'm a newbie.
On my windows PC I used Copytrans iLibs to manage multiple multiple (different) libraries on 5 IOS devices (iPod touch, 2x iPhones and 2x iPad's). It worked a treat.
But I've just changed platforms to an iMac and after migrating all my data over I find iTunes is absolutely full of all music from all devices and 60 odd Apps. Everything is in the one account. I went to Copytrans website only to find they don't have Mac compatible Apps 
How on earth can I restore iTunes to reflect each of the libraries on each of the devices? Is it in fact possible?
I really would appreciate help on this guys. Thanks in advance!
Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic