Do you get a more detailed description of the error on the error page (usually below the HRESULT code)?
And ColdFusion installs just fine on IIS 7+ for most users, if they follow all of the installation instructions carefully (especially with regard to the IIS component prerequisites). Most of the time (but not always) when people have posted here with errors following the installation, it turns out to be that they didn't follow all of the instructions.
-Carl V.