Which version of Windows 7 do Windows 7 tablets run?

I was just wondering which version is used.....is it one which is specially optimized for tablets running Windows 7.....can it be downloaded and tried on my touch screen net book???

My tablet came with windows 7 home premium, there is no optimized version of Win7 for tablets and touch and tbh trying to use Win7 on touch devices pretty much sucks.

You may want to try the Windows 8 developers preview which although not the final product, it's more geared to touch devices http://www.eightforums.com/windows-8-news/2221-windows-8-developer-preview-release.html