On a Windows 7 Professional system, it seems not possible to run New-SelfSignedCertificate. I could on a Windows 10 system.
Yes, the shell was started with \"Run As
Have to install AzureRM module to use azure commands through powershell. You can use below command to do it.
Install-Module -Name AzureRM -AllowClobber
As stated in the comments above, this isn't available in Windows 7.
However, if you're looking for something with a similar API and capability, then I have used & can recommend this from Microsoft Script Centre:
https://gallery.technet.microsoft.com/scriptcenter/self-signed-certificate-5920a7c6