Delete a site collection SharePoint Server 2010

After you perform this procedure, the site collection and all of its content and user information will be permanently destroyed.


Please follow the below mentioned steps to delete the site collection:

1.     Verify that you have the following administrative credentials:

      To delete a site collection, the user account that is performing this procedure must be a member of the Farm Administrators SharePoint group.

2.     On the Central Administration Web site, on the Quick Launch, click Application Management

3.     On the Application Management page, in the Site Collections section, click Delete a site collection.

4.     On the Delete Site Collection page, in the Site Collection drop-down list, click the down arrow, and then click Change Site Collection.
The Select Site Collection dialog box appears.

5.     In the Web Application drop-down, click the down arrow, and then click Change Web Application.
The Select Web Application dialog box appears.

6.     Select the name of the Web application that contains the site collection that you want to delete. Relative URLs of sites in the site collections of the Web application that you have selected appear on the Select Site Collection dialog box.

7.     Click the relative URL of the site collection that you want to delete, and then click OK.

8.     Read the Warning and cross-check that the site collection information is correct.

9.     On the Delete Site Collection page, click Delete.

        The site collection will be successfully deleted.

Refference:

1. PowerShell To Delete Site Collection

2. SharePoint Tutorial: How to delete a SharePoint site collection

3. Gradual Site Delete in SharePoint 2010

4. Delete site collection