Correct "stripes" in VHS record
Those are interlacing artifacts. They become visible when the motion in the video is faster than the field rate, so that when both fields are combined into a progressive scan image, the movement is visible in a single frame. They can be removed with a de-interlace filter. I've never personally used one with Virtualdub, but several are available:


MSU
Smart Deinterlace
vddeint
Various older ones