Step by step DVD ripping:
  1. Place DVD in your DVD drive
  2. Open DVD decrypter
  3. Set DVD decrypter to IFO mode
  4. Rip the .VOB files from the DVDs
  5. Open DGIndex
  6. Load all of your VOB files into it
  7. Preview your project file
  8. Note down the settings it gives you
  9. Save your project (it's a d2v file]

There are 2 ways to go from here
Method 1
  1. Open the .avs file that is in the place you put the .d2v file in VirtualDubMod
  2. Apply the avisynth filters you need using the script editor, then press F5 to see how they look and save it
  3. Choose which parts of the footage you want to use using the Home and End keys to select
  4. Save the clips you want as either HuffYUV or Lagarith (they will be very big)
  5. Import the finished clips into Windows Movie Maker.


Method 2
  1. Use VFAPI to make an avi wrapper for the .avs file
  2. Import this fake avi into Windows Movie Maker


Method 1 is the only one I've personally tested but method 2 should work in theory. Avs files are just tricky to work with because they take a lot of processing power.

How much RAM have you got?

You can PM me if you need more explaining.