Hey folks we came to know by a tweet from @Redsn0w_testers that they will release the Redsn0w 0.9.7b4 today and after that Windows version will be released.
@redsn0w_testers: Today’s B4 will eliminate seperate usbmuxd process ( So many more mac users can use it). After that, expand to windows.
This untether is a ‘backup plan’ from the iPhone Dev-Team. It requires access to the iOS 4.2b3 firmware and your iOS 4.2b3 SHSH blobs saved.
Currently, the untethered jailbreak is for Mac only but the next update will bring Windows support.