use cpu-z http://www.cpuid.com/cpuz.php
or piriform's speccy http://www.piriform.com/speccy
or hwmonitor software to check your system specifications.
you can also check from within your pc, right click the computer icon on desktop and select "properties".
in windows 7, click start button and in the search box, type system, select "system information", after loading, you'll see the type of your processor in the "processor" section.