An Error message called "An endpoint named 'PowerShell' has already been defined" my occur when you try to provision new VM via PowerShell. This error is a result of running "Add-AzureEndpoint -LocalPort 5986 -Name 'PowerShell' -Protocol tcp -PublicPort 5986" Azure module while provisioning new VM via New-AzureVMConfig. Azure finds this End Point already existing and will error out with "An endpoint named 'PowerShell' has already been defined for this VM." Removing this Azure cmdlets will make your PowerShell script work and will provision VM with the right PowerShell End Point.

Detailed Error message is presented below.

Add-AzureEndpoint : The pipeline has been stopped.
At line:1 char:325
+ New-AzureVMConfig -Name "MyVMName -InstanceSize "Medium" -ImageName "MyVMName ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : CloseError: (:) [Add-AzureEndpoint], PipelineStoppedException
+ FullyQualifiedErrorId : Microsoft.WindowsAzure.Commands.ServiceManagement.IaaS.Endpoints.AddAzureEndpoint

Add-AzureEndpoint : An endpoint named 'PowerShell' has already been defined for this VM. Specify a different endpoint
name or use Set-Endpoint to change the configuration settings of the existing endpoint.
At line:1 char:325
+ New-AzureVMConfig -Name "MyVMName -InstanceSize "Medium" -ImageName "MyVMName ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidData: (:) [Add-AzureEndpoint], InvalidOperationException
+ FullyQualifiedErrorId : Microsoft.WindowsAzure.Commands.ServiceManagement.IaaS.Endpoints.AddAzureEndpoint