No, shake is no longer evailable form windows wehn you step up from thet version number.
Offcourse you can have older shakes jjjustthat theres no way to leegaly get shake for windows anymore. So unless your one of the very small number people/ studios in the world that actualy bought it then talking and saying that yoru using shake 2.5.1... on widows your boadcasting using a piratted version. And then you would have been contacted ages ago about switching.