Just bought a Nikon D3100, having trouble editing its HD video on my laptop?

Tried using Windows Movie Maker, Windows Live Movie Maker and Videopad Video Editor (free NCS Software download) and none of these are working as the vision lags really badly although the sound is playing fine. What is the problem and how do I solve it quickly? Urgent help needed guys.

Added (1). My laptop is just under 2 years old

Editing HD video requires a fast computer.

Have you tried copying the video to your computer first as the hard drive on your computer will be far faster than the memory card?

How old is your laptop? You may not have enough computer.

Your laptop is not good enough.

You need quicktime player pro
google it

You need power and fast access to the data. Having a computer able to handle hd viewing won't be enough to edit big hd files from a hddslr. I'm no expert in computer but ask someone in a shop and they should ba able to help. They will probably direct you to a more adequate computer with plenty of ram

HD editing requires a real editor not some freebie. Try using Adobe Premier Elements which retails for around $100. Its the consumer version of Adobe Premier Pro which has no problem with HD video.