CS5.1 overrides CS5 registry entries, how do I get the photoshop installation location safely?

Hi there,

I'm creating a installer for my Photoshop plugins, so I need to find out Photoshop installation directory. I did this by looking for registry 'HKEY_LOCAL_MACHINE\SOFTWARE\Adobe\Photoshop\', but I found that CS5.1 will override the CS5 registry entries - they are both in ’HKEY_LOCAL_MACHINE\SOFTWARE\Adobe\Photoshop\12.0‘

So how can I distinguish CS5 and CS5.1 in the registry? Or how can I get the correct installation direcotry for both CS5.1 and CS5?

Thanks,

Daniel