Apple today rolled out a new version of iTunes specifically for Windows users. Windows-only iTunes updates are rare for Apple, but the changelog says that today's release fixes some significant bugs related to Outlook-device syncing, as well as an audio playback glitch.
Users can update to 12.1.1 by either visiting the Updates section from the Updates tab within iTunes, or they can visit Apple's website and download the software in its entirety. Windows users must be running Windows Vista 64-bit or later, and have 400MB free space.