Is there a way to take a screenshot of the Render Window?

Print Scrn > paste into MS Paint is what I usually do. There doesn't appear to be any other way within the CS itself.

The free version of FRAPS has a screenshot function that should work nicely. Otherwise, use Hanaisse's suggestion.

Shift + Alt + PrtScn takes screenshot of active window only.

in which program ?

Try irfanview - highly customizable capture screen function
anfd it is free
fraps creates lots of junk in my pC I think
folders registry keys etc etc

I'm pretty sure you don't need the Shift for that, just Alt + PrtScn will do. In fact using the Shift as well may turn on High Contrast mode if you have the Accessibility feature enabled. There's also a Ctrl + PrtScn variant, which IIRC will print an application window with (or was it without?) any dialogs it popped up, or something similar. I tend only to use plain PrtScn for the whole desktop window, or the Alt + PrtScn for the currently active window/dialog.

This is a Windows Explorer function, operating on the desktop window and all its children, so it's not application-specific.

Thanks - indeed using the Shift does turn on High Contrast mode

Thanks for the replies. I was afraid there wasn't a way within the CS itself.

Oh, just Alt + PrtScn! Great! I don't know where did I get that Shift from!