REGEDIT4

[HKEY_CLASSES_ROOT\avifile\Extensions\AVS]
@="{E6D6B700-124D-11D4-86F3-DB80AFD98778}"

[HKEY_CLASSES_ROOT\Media Type\Extensions\.avs]
"Source Filter"="{D3588AB0-0781-11CE-B03A-0020AF0BA770}"

[HKEY_CLASSES_ROOT\CLSID\{E6D6B700-124D-11D4-86F3-DB80AFD98778}]
@="Avisynth"

[HKEY_CLASSES_ROOT\CLSID\{E6D6B700-124D-11D4-86F3-DB80AFD98778}\InProcServer32]
@="avisynth.dll"
"ThreadingModel"="Apartment"

