Step 1: Log into your Drupal 7 Admin dashboard.
Step 2: Using the top menu bar, find and click on the Configuration option.
Step 3: This is the Configuration screen. Locate the People category clicking on the Account Settings link.
Step 4: You are now on the the Account Settings screen. Be sure you are on the Settings Tab. This is found in the upper right part of the screen.
Step 5: Move down the screen to the Registration and cancellation section. Find the Who can register accounts? setting and select your choice from the radio buttons.
Administrators Only — Only admins can enter and register new people. The most restrictive.
Visitors — Anyone can register. The least restrictive.
Visitors, but administrator approval is required — The middle ground. Visitors can register but admins have to activate the
Step 6: Click on the Save Configuration button at the bottom of the screen