Not tested Painter 11 yet on Win7 RC 64bit, but I'm running Painter IX.5 on it and it runs fine.
The only thing I noticed so far is stuttering movement of the palettes and dialogs when dragging them (eg to dock them underneath eachother)
Isi t safe to install 2 versions of Painter on the same windows?
I'm still thinking about this... since PIX.5 runs quite well, perhaps I should not take any risks...