Yes I figured it out, but many thanks for your quick response. I did it by using two layers, making the first one transparent and then adding a new layer with the circle. But I will try your method. And you were right about the file format.
Bert
I'm trying to create an image (a simple circle) with a transparent background so I can overlay it in my video program. But the background shows white in both paint.net and the video program. Would appreciate somebody telling me what I'm not getting!
Thanks
Bert