I have 8GB RAM and while starting the sandbox, the booting process is taking a lot of time...its running from last 1 hour or so...Pls advice.
When you say "I have 8GB RAM", do you mean allocated to the VM or total on your computer. The VM itself needs at least 8GB of RAM. If your computer only has 8GB of RAM, you will have difficulties running the Sandbox.
If you have a total of 8 GB of RAM you might consider using the Hortonworks HDP Sandbox on Azure. Here is a tutorial to walk you through that process: