Steps are as follows-
1.Click on start button and then click on Control Panel.
2. Then Click on Clock, language and region option.
3. A window will open click on Region and language button.
4. A new window will open named Region and language button in which click on Additional Settings.
5. A new window will open named Customize Format in which click on Time.
6. In the Customize Format window change the value of time formats for both AM and PM as hh:mm:tt .
You can give different names for both AM and PM. Set your name and then click OK.
In the Toolbar the name is visible..