traktor pro 2 sound distortion, dropouts help me>>>

I cant get traktor to sound playable. Its distorted, cracking, dropping out. I have tried ASIO4All. The sound is bad no matter if I hook up the Z1 traktor controller or not.. Sometimes I just want to use tracktor without the Z1. I have tried different buffer rates and latency settings. Maybe my processor is screwed? Or is it a RAM issue? Do I need to just forget it because this Sony Vaio laptop is not good enough for real time audio? I need some help Please. Someone please take me step by step what to do.

Sony Vaio E series. 500 gb hard drive. 4G RAM. i3 processor. Windows 7 64 bit.
Realtek HD internal soundcard
Traktor Z1 controller sometimes
Traktor Pro 2