How to record PC screen and speed up the video?

Wanting to know the best and most cost effective way to record my PC screen then speed the video up when its done. Wanting to record myself doing some digital in artrage, gimp, and corel painter. And speed up the video to be able to watch the paintings come together a lot faster than the actual hours it takes.

Also would like to know a good screen recorder for gaming that doesn't make your PC lag alot. Tried using Microsoft expression encoder 4 to record minecraft and it was horrible.

Added (1). My computer is running Windows 7 64 bit. I7 Q840, Dual Nvidia 285m in SLI, 8gb RAM.

Added (2). Camstudio seems to be full of adware, Camstudio and Sony Vegas arent exactly what I'd call cost effective. I don't make videos often and recording my screen and speeding it up arent worth hundreds of dollars to me. Looking for between the price range of free and maybe $20 to $30

Camstudio or Camtasia and Sony Vegas

It's depend on your PC.

Try Bandicam or Fraps to record, and they both have trials where you can test how much they lag your PC for free before you buy them. And your computer should have Windows Movie maker to speed it up, but if it doesn't, you can download it from the Microsoft website. If you want a better video editor, try VideoPad, http://www.nchsoftware.com/videopad/ click the download now to get the free version.