Overriding Tabs Using a Standard List Controller

Pages that use standard list controllers can be used to override tabs. For example, if you create a page named overrideAccountTab that is associated with the Account standard list controller:
<apex:page standardController="Account" recordSetVar="accounts" tabStyle="account">
  <apex:pageBlock >
    <apex:pageBlockTable value="{!accounts}" var="a">
      <apex:column value="{!a.name}"/>
    </apex:pageBlockTable>
  </apex:pageBlock>
</apex:page>
Then, you can override the Account tab to display that page instead of the standard Account home page.
To override the tab for Account:
  1. From Setup, click Customize | Accounts | Buttons, Links, and Actions.
  2. Click Edit for the Accounts Tab.
  3. From the Visualforce Page drop-down list, select the overrideAccountTab page.
  4. Click Save.
Note
Make sure you have made this page available to all your users by setting the page level security appropriately.
© Copyright 2000–2014 salesforce.com, inc. All rights reserved.
Various trademarks held by their respective owners.