ASF / WMV conversion guide
You'll need the following software in this guide:
Step 0: Preparations
Install Graphedit and Avisynth as per the readme files that can be found in both packages.
Then play your ASF/WMV File in Windows Media Player 6.4 (c:\program files\windows media player\mplayer2.exe). During playback right click on the movie, and select statistics:
Then look 
  at the Actual rate. It will normally fluctuate a little, especially if you have 
  a lot of other tasks running in the background (in this case I had TMPG running 
  so my CPU was maxed out). In any case, if it's around 23-24fps the source has 
  a framerate of 23.976fps. If it's around 29-30fps it's framerate is 29.97fps 
  and if it's around 25fps it's actually 25.00fps.
  
  Step 1: TMPG Setup
Start up TMPG and prepare it for .asf/.wmv input.
Step 2: Encoding