By A Web Design
To activate Akismet plugin in your WordPress driven Blog, login to WordPress as administrator, by simply entering the url_of_your_website/wp-admin in your Browser. Enter the appropriate username and password { which was provided while installing Wordpress } and then click on Log In as shown in Diagram 1.

Diagram 1
After logging in as WordPress Admin, a Dashboard page opens as shown in Diagram 2.
The Dashboard provides access to different WordPress functions and features.

Diagram 2
In the left menu, locate the link Plugins. Click on Plugins, from the drop down menu that appears click on Plugins as shown in Diagram 3.

Diagram 3
A list of all plugin is displayed as shown in Diagram 4. Locate the Akismet from the installed plugin.

Diagram 4
Click on the Activate link to activate the plugin as shown in Diagram 5.
Diagram 5
Once you have activated Akismet you will see a message that the plugin is activated, along with that you will also see a message that you need to add an Akismet API key for it to work as shown in Diagram 6.
NOTE: Many new users may not have an Akismet API key, to get one you have to sign up to Akismet.com and retrieve API Key .
Diagram 6
Visit the Akismet.com site by clicking the “Visit plugin site” link of the specific plugin as shown in Diagram 7.
Diagram 7
When the Akismet.com website opens in the Browser window, click on the button “Sign up for Akismet “in the right hand side to get the Akismet API Key as shown in Diagram 8.
Diagram 8
Select the appropriate options for the plan and click on CONTINUE as shown in Diagram 9.
Diagram 9
Fill in the Form with the necessary details it requires such as First Name, Last name, Email and Confirm email as shown in Diagram 10.
Click on CONTINUE as shown in Diagram 10.
Diagram 10
As you click on continue a successful message appears saying that the Akismet subscription is active and an email with API Key is sent to the emailid provided while filling the above form.
Check your email and follow the instruction to activate Akismet in WordPress using the API Key.
Diagram 11
NOTE: The API gives you direct access to the Akismet service.
The API key is a string of letters and numbers that acts like a username/password, allowing you to login to the Akismet service. You should never give your API key to anyone, as this will give them access to your account.
On activating the plugin you will see a message that you need to add an Akismet API key for it to work.
Click on “enter your Akismet API key” link { after obtaining the API key following the steps described above }, as shown in Diagram 12.
Diagram 12
Copy / paste the API key received via Email in the textbox as shown in Diagram 13.
On the same page you can also choose to automatically discard spam comments older than one month. This will help you save some database space.
Click on Update options in order to save the changes made in configuration.
Diagram 13
The message “Options saved.” and “Your Key has been verified. Happy blogging!” is displayed as shown in Diagram 14.
Diagram 14
In the frontend, each time a new comment, trackback, or pingback is added to your site, it's submitted to the Akismet web service which runs hundreds of tests on the comment and returns a thumbs up or thumbs down. As a result, you don't have to waste your time sorting through and deleting spammy comments from your blog.
Diagram 15