error 404 admin deshboard disappeard

Hello,
My admin page just disappeard…
as you can see here

http://www.scoiattoloequestriancentre.com/wp-admin/upgrade.php?_wp_http_referer=%2Fwp-admin%2F

– I removed the Plugin folder
– I changed the .Httaccess

nothing changed still gives me error

any idea??

thanks in advance for your help!