Here is how I did it, did not have to use PowerShell and my original VM still worked after.
Result if you use sysprep
from documentation:
Once you have run sysprep on an VM it is considered generalized and it
cannot be restarted. The process of generalizing a VM is not
reversible. If you need to keep the original VM functioning, you
should take a copy of the VM and generalize the copy.
https://docs.microsoft.com/en-us/azure/virtual-machines/windows/capture-image-resource?toc=%2Fazure%2Fvirtual-machines%2Fwindows%2Fclassic%2Ftoc.json
Steps:
Start by copying a disk. Create a snapshot, then create a disk from the snapshot. This allows you to keep the original VHD as a fall back.
- In the left menu, click on All resources.
- In the All types drop-down, de-select Select all and then scroll down and select Disks to find the available disks.
- Click on the disk that you would like to use. The Overview page for the disk opens.
- In the Overview page, on the menu at the top, click + Create snapshot.
- Type a name for the snapshot.
- Choose a Resource group for the snapshot. You can either use an existing resource group or create a new one.
- Choose whether to use standard (HDD) or Premium (SDD) storage.
- When you are done, click Create to create the snapshot.
- Once the snapshot has been created, click on + Create a resource in the left menu.
- In the search bar, type managed disk and select Managed Disks from the list.
- On the Managed Disks page, click Create.
- Type a name for the disk.
- Choose a Resource group for the disk. You can either use an existing resource group or create a new one. This will also be the resource group where you create the VM from the disk.
- Choose whether to use standard (HDD) or Premium (SDD) storage.
- In Source type, make sure Snapshot is selected.
- In the Source snapshot drop-down, select the snapshot you want to use.
- Make any other adjustments as needed and then click Create to create the disk.
Create a VM from a disk
Once you have the managed disk VHD that you want to use, you can create the VM in the portal.
- In the left menu, click on All resources.
- In the All types drop-down, de-select Select all and then scroll down and select Disks to find the available disks.
- Click on the disk that you would like to use. The Overview page for the disk opens. In the Overview page, make sure that DISK STATE is listed as Unattached. If it isn't, you might need to either detach the disk from the VM or delete the VM to free up the disk.
- In the menu at the top of the pane, click + Create VM.
- On the Basics page for the new VM, type in a name and select either an existing resource group or create a new one.
- On the Size page, select a VM size page and then click Select.
- On the Settings page, you can either let the portal create all new resources or you can select an existing Virtual network and Network security group. The portal always create a new NIC and public IP address for the new VM.
- Make any changes to the monitoring options and add any extensions as needed.
- When you are done, click OK.
- If the VM configuration passes validation, click OK to start the deployment.
I choose to create a new virtual network since the servers themselves did not need any local connections.
https://docs.microsoft.com/en-us/azure/virtual-machines/windows/create-vm-specialized-portal#copy-a-disk