how to take print screen during windows installion?
Print screen is a function of windows. How can you use that function when you are installing and that function is not installed? You can use camera to take pics.
Or run it inside of a virtual machine, like VMWare or Virtual PC. Virtual PC got bought by Microsoft a few years back, and as a result, they've made it free for Windows users to download (I seem to recall they also took out the ability to install non-Microsoft OSs, but that's a different matter): http://www.microsoft.com/windows/virtual-pc/default.aspx
Pro Tip: In Windows, using ALT + PrtScrn copies only the currently selected window (e.g. the one in which your virtual machine is running), instead of the entire desktop: http://en.wikipedia.org/wiki/Print_screen