Vista SP1 no directx 10.1

[fallen2004]

I bought Vista Premium X64 with SP1 included and have installed it but when i go run/dxdiag and look at the Directx diagnostic tool it says my direct X version is: DirectX 10
how can i get 10.1 as i cant find a download for it?

 

[badge]

http://www.microsoft.com/downloads/details.aspx?FamilyID=2da43d38-db71-4c1b-bc6a-9b6652cd92a3&DisplayLang=en