To deploy a virtual machine within a Virtual Network, Click on New->Click on Compute-> Select any image to create a Vm such as Windows Server 2008 R2 SP1 -> Select a Deployment Model (Classic or Resource Manager)
Provide unique Name, User name, Password and location details and click ok.
Select Virtual machine size based on preference or requirement. We have selected here DS1.
In settings, provide details on Virtual Network and Subnets available in selected Virtual Network-> Click Ok.
Verify Summery details where we can see Virtual Network and subnets related information. Click Ok.
It will take some time to deploy a Virtual machine. Once it is created. Verify IP address of a virtual machine.
The difference here will be the allocated IP address. If a VM is allocated outside virtual network then it will have a random IP address. If we deploy a virtual machine in a virtual network then we will see IP address from the range assigned to Subnet of an assigned virtual network