I'm running vista and it gives a higher hashrate.

So you are the one still running Vista!! lol!!!
I would think that a clean/bare install of Window 8.1 and/or Window 7 would run faster than Vista.
Vista had core modifications that were abandoned, due to stability, in favor of a new approach in Windows 7.
Stable as a rock.
On cuda mining nvidia mining it does do a higher hashrate on memory type coins.
I should add that to btc 81 pro if it would take it.

Shocking!! I am glad it works for you.
I had that computer hashing with 2 750ti's for 2 years now and that little thing has been good to me.

Something about windows as we went from vista to 7 to 8.1 then 10... that the hashrates went down for memory type coins.
I remember doing scrypt jane and it was hashing at about 10% higher hash then my windows 8.1.
I think someone said that it was related to windows allocating memory.