Magento 2 : Error 404 not found at magento 2 admin login page
This is a general error, usually occurs when you transfer your magento-2 installation from one location to another.
The reason behind this error is that the value store_id and website_id for the admin should be 0 , but when you import the database to a new server, somehow these values are not set to 0.
So to solve this error you will need to make some changes in the database tables itself.
SET FOREIGN_KEY_CHECKS=0;
UPDATE store SET store_id = 0 WHERE code='admin';
UPDATE store_group SET group_id = 0 WHERE name='Default';
UPDATE store_website SET website_id = 0 WHERE code='admin';
UPDATE customer_group SET customer_group_id = 0 WHERE customer_group_code='NOT LOGGED IN';
SET FOREIGN_KEY_CHECKS=1;