If OpenGL is not the problem, i read often that window vista/seven have a different kind of file managing of everything that end into the “Program Files” directory.
Install then Blender directly on the root of your hard drive, by example if your hard drive is C:\ , install it under C:\Blender instead of C:\Program Files\Blender.
Additionally, that could get some user data security thing too, as there’s many new things regarding this in window 7 that could get in the way of Blender.
To see if it’s that, after installing Blender in C:\Blender, in that directory you should see a folder named " 2.62 " (if you downloaded the latest official release).
Inside of that " 2.62 " folder , there are several one, but create a new one manually, and name it exactly :
So you should have \Blender\2.62\config\
Launch Blender now to see if it works