In Windows 8 capture the whole screen is real easy. You simply press Windows Key + Print Screen Key. The captured picture will be stored in your Pictures folder under Screenshots.
If you want to capture a window or part of the screen, you can still use Snipping Tool. (Press Windows key and type Snip, select Snipping Tool from the search results). Snipping Tool is available since Windows 7.
Anand, the Architect 