How to use HG(Mercurial) in command prompt?

How can I open the hg in the command prompt in any directory?

I have tried setting classpath. But nothing works..

I need to use Hg like below picture wherever am in the directory.

enter image description here

Solution

You must have path to C:\Program Files\TortoiseHg\ in your PATH variable

Open Control Panel -> System -> Advanced System Settings -> Advanced Tab -> Environment Variables

Make sure that under PATH variable you have C:\Program Files\TortoiseHg\ included