I have a hp-dv6 8 gb of ram, 640gb of storage,AMD A8-3500 quad core 1.8ghz to 2.4ghz dual. the video is one that i took from a website, then converted it into a wmv file. I originally had trouble importing but thats a different question. I started to play it then the video would be working then the audio would lag back 2 seconds then I cut off one of the audio tracks to see a difference then i cut off the other and ran with the plain video audio. Still no change.
You'd be better off transcoding on import to one of the I-Frame Only codecs in Lightworks like MPEG 2 I Frame or DVC PRO 100. These will give you relatively big files but will allow you to edit smoothly and then you can reduce the file size when you've finished editing.