admin Login shows a blank white page after signing in. - Joomla! Forum - community, help and support

my site hacked. restored , cant access admin page. blank white page. please help.
404 - component not found
you may not able visit page because of:
an out-of-date bookmark/favourite
a search engine has out-of-date listing site
a mistyped address
you have no access page
the requested resource not found.
an error has occurred while processing request.
please try 1 of following pages:
home page
if difficulties persist, please contact system administrator of site.
component not found