We want to install erpnext on windows 10 machine we have downloaded virtual box software but we are unable to download production image file

we want to install erpnext on windows 10 machine we have downloaded virtual box software but we are unable to download production image file from Get Started - ERPNext Foundation .when we click on download button http://build.erpnext.com/ERPNext-Production.ova this site cant be reached.
kindly suggest.