OK, speed chaecking of what: The CPU itself, or your ISP or what speed! There is nothing you can do for your speed, unless you wish to overclock, and in that case you risk blowing up your PC is you cannot cool it correctly!!!
Get into the desktop, and hit the windows key. On this menu select system. On the next splash screen there will be a window that looks like this:
You will notice, the PC that I am using has a clock speed of 2.13Ghz! that is your PC speed.
If you wish to measure the ISP, open a browser and go to speedtest.net!