Maybe this one will work, maybe not. I only have one monitor so I can only test it that way.
https
/www.freewarefiles.com/Desktop-Christmas-Snow_program_94720.html
It uses more CPU that DesktopSnow.
It looks better than DesktopSnow in my opinion, but the flakes are tiny.
Like the other program, if you have a program that has it's "Always On Top" setting to yes, then the flakes will be behind that program. I have a feeling that you'll run into that problem with most "snow flake" programs.
Also be suspicious as these are the types of programs that malware/adware/scammers target and try to get people to install so they can install their own hidden software along with it. I've checked these two and feel they are safe.
Maybe someone...