FireCore has released now Seas0nPass tethered jailbreak tool for Apple TV 2G over iOS 4.3 for Windows users as few days back Seas0nPass 0.7.2 iOS 4.3 for Mac was out there.
You can follow the instructions to jailbreak Apple TV 2G with Seas0nPass on iOS 4.3 by clicking on the integrated link.
Download Seas0nPass for Windows
Download iOS 4.3 for Apple TV 2G
Download iTunes 10.2.1