I've been using Winamp for a while and love milkdrop - just not how it doesn't seem to be able to fill both screens when in desktop / fullscreen mode regardless of what I do in the settings. So, I got tired of waiting for a fix ( and given there are threads in the support forum about this from years
ago without any real resolution, I am probably not alone ) and made a workaround for myself. It, in essence, will detect the bounds of all your connected screens and will resize milkdrop to fit that space.
So, if you have the same issue as I do, this might be a temporary fix until the issue is, hopefully, eventually fixed.
This will support any version of milkdrop that labels itself "MilkDrop 2" when windowed, and you must have milkdrop in windowed mode - these are limitations of the method I used to resize the window.
The program currently assumes that the primary screen is either the tallest resolution, or all other monitors connected are the same height. If this is an issue for anyone, I'll change that.
Requires .Net 3.5 to use.
Just click the milk carton to resize, and then you can close the program, it doesn't need to keep running. To restore the milkdrop window, I personally just toggle the desktop mode to return to windowed mode.
If anyone has trouble, I'll do what I can to try and fix it for them.