Windows 7 Embedded VM in Azure
Solution 1:
You need to install the Hyper-V Integration Services in your VM before migrating it to Azure, otherwise it will not have the appropriate drivers to run in Hyper-V (and thus in Azure); specifically, it will be lacking the NIC drivers and thus will have no networking.
However, the HVIS ISO image is not available anymore on Windows Server 2016 and 2019, because Hyper-V drivers have been integrated into Windows for a while; the only way to get a copy of it is to retrieve it from the Windows Server 2012 R2 install media or from a Windows Server 2012 R2 server with the Hyper-V role installed, as documented here. There are also various copies of it floating around the Internet, such as described here.