Totally different animal.
No similarities whatsoever. In regard to Creed, the first release of Windsor, a numbered limited edition sold through Saks, is considerably different from the second widely distributed version. They had it right on the first go and then lost their way.
D R Harris Windsor is a nice product line. I have been using the cream, aftershave, and EdT. Good value but when it comes to scent it is far, very far, from the vastly superior Creed product.
Have both, my above post is direct personal experience based, if it helps the OP.I don't know if DRH Windsor is a knockoff, as I don't have Creed Windsor (but I do have Creed Bois Du Portugal and really like it); however, the DRH Windsor is very nice. It's old school and masculine. I always get compliments on it.