SharePoint 2010 - Central Admin Create/Extend Web Application button on Ribbon are disabled

There can be more than one scenario for this issue.

Scenario 1

The Internet explorer is not opened using the administrator privileges. So, Open the Internet Explorer with "Run as Administrator" privileges. How to do this?

1. Just right click on the IE icon.

2. There you can see a menu as "Run as Administrator".

Scenario 2

This may be due to security problem on Win 7. Follow the steps below to solve the issue.

1. Login as Administrator to the machine where SharePoint is installed.
2. Open User Account Control Setting from C ontrol Panel -->System and Security-->Change User Account Control settings and set the Slider bar to "Never Notify "