Yes, I do know. When the Ghost 2.5 product was released, Windows 7 was still in development, so the most recent release of WinPE was based on the Vista kernel, which was the most recent at that time.
Since the version 3.0 product was not released several years ago, and the original Ghost development team was disbanded, only incremental patches have been released since that time. Fortunately, the product has now been subject to some serious development and version 3 is due for release in the middle of next month. This will feature a much more up to date release of WinPE based, I believe, on the Windows 8 kernel.