How do I take a screenshot with out any software?

FOR WINDOWS XP ONLY  How do I take a screenshot?
		press		=	Windows captures the entire screen and copies it to the (invisible) clipboard.
Where can I find that key?
					Look for this group of keys at the upper right of your keyboard. Note: Print Screen (PrtScn) might have been abbreviated differently on your keyboard.
How do I take a screenshot of a single window?
hold down		and press		=	Windows captures only the currently active window and copies it to the clipboard.
I guess it’s in the clipboard now. How can I paste it into a document or something?
hold down		and press		=	Windows pastes the screenshot (that is in the clipboard) into a document or image you are currently editing.
Where should I paste it? I just need a (graphics) file.
Start “Paint” Paste Save