What cpu for you PC do you have?

Intel Pentium 4 3.0GHz/ Amd Sempron 3600 or better.

Intel Core 2 Duo E4400/ Amd Athlon 64 X2 Dual Core 4000 or better.

Intel Core 2 Quad Q6400/Amd Phenom 9500 Quad-Core or better.

Intel Intel Core i3-4330T/Amd Phenom II X4 955 Black Edition or better.

Intel Core i7-3770/ Amd FX-8350 or better.