Removing X-Powered-By-Plesk: PleskWin

Hi,
does anyone know of to get ride of <X-Powered-By-Plesk: PleskWin> header that is added by plesk ?

I know I can access IIS and remove it on a domain by domain basis but since it's not listed in the IIS default Headers, I don't know how to remove it for every domains (new and old)

Thanks

edit: Using Plesk 11 latest updates on Windows 2012 server fully updated as well