Drupal 8.2.1 not able to install on Ubuntu 16.04 server

I downloaded and installed Drupal 8.2.1 on Ubuntu 16.0.4 server successfully. I can login as admin successfully. But all urls on the Drupal site do not open,

[http://server/drupal/admin/appearance] gives following error

The requested URL [/drupal/admin/appearance] was not found on this server.

I tried to verify if the folder /var/www/html/drupal/admin is created or not on the Ubuntu 16.04 the server. But the folder isnt created. Similarly other folders are not created.
http://server/drupal/node/add again gave same error.
The requested URL [/drupal/admin/appearance] was not found on this server.

I tried installation with Drupal 7. But exactly same thing happened.

I would like to successfully install Drupal 8.2.1 on Ubuntu 16.04 server. Any clues to the problems please.

Drupal version: 


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