An HDMI to VGA adapter is not permitted by the HDMI adopter's agreement - in other words, the vendor was, by their agreements, not supposed to be able to sell you that.
So, you're on your own as to whether or not it will work. Try it and see what happens.
BTW, any conversion from HDMI to any type of high definition analog output is prohibitted. 480i/p is still permitted. If your VGA device only generates 480p, then it may have been OK but you won't like the picture.