AFAIK there is no protection that can prevent converting VHS to digital format. Macrovision protection prevents copying to another VHS cassette.

I don't see any problem converting VHS to DVD. You should have some kind of video capture device. It could be video card with TV-in, TV-tuner, capture card. You may even use digital video camera to convert VHS to digital format.

Connect video out of VHS recorder to video in of your computer device, audio out of VHS recorder to line-in of your sound card and capture.

Lots of programs can capture videos. Some of them can record sound as well.