To enable iCloud on your Windows PC (Windows 7 or 8 required), first set up iCloud on your other devices, then install the iCloud Control Panel for Windows.
Open the iCloud Control Panel and enter the Apple ID you used to create your iCloud account. Select the iCloud services you’d like to enable and click Apply.
To enable automatic downloads for your music, apps, and books, open iTunes > Edit > Preferences > Store and select Music, Apps, and Books.*