direct x question

dumb questions guys. So i upgraded from xp to vista about 2 weeks ago. I thought vista installed direct x 10 upon installation, but when i was installing a game today, it installed direct x 9.0c thinking it was the latest version. How do i check which version i have, and if it isnt ten, how can i get it. I searched microsoft.com for direct x 10 but got nothing useful,direct x question
bump, asnwer me no matter how dumb i amdirect x question
I've installed games which supposedly ''install'' DX 9.0c on Vista, but no matter what, it always stays at version 10 so no worries.
Oh, and to check what version of DirectX you have:Click the START/Windows button, then in the search box type DXDIAG and click the icon that shows up .. now, when the window pops up, near the bottom it should say ''Direct X version: DirectX 10''
thanks, i was confused cause usually if u have the latest version of direct x, it will check your comoputer but not install, this game actually installed it after checking.