Creating a vhdx template for deploying your VMs (Hyper-V)

Background story (that you can safely ignore)

I have been using the template to deploy new servers at work.  Now that I am spending more time in my home lab, I realize it is quite time consuming to always build a VM from scratch.  I decided to create a template so that I can easily deploy a new server in minutes. 

1. Create a new VM and install the OS of your choice.  Note that if you use both Gen 1 and Gen 2 VM, you will need to create a template for each.
2. Once you have the OS installed, run all the windows updates and install any windows features that you normally need.  (For my home lab, I have Telnet Client and IIS installed)
3. I only went as far as installing the OS, running windows updates, and installing necessary windows features on my template.  I will leave installing applications and additional roles when I configure the server further.
4. Without joining the machine a domain, open CMD as an administrator.
5. Run this command in the CMD

C:\Windows\System32\Sysprep\sysprep.exe /oobe /Generalize /Shutdown /Mode:vm

This command will generalize any system specific data from this machine.  The next time it boots, it will act as if it is a different machine.  This way, you can just rename the VM and then join it to the domain, skipping the OS installation and running windows updates.

6. After the machine shutdown, copy the vhdx to a network shared and rename the file to something that can tell you what template it is.  I called mine “Server2019DataCenterGen1”
7. With the vhdx copied to a different location, go ahead and delete/clean up the VM that you created for this template. 
8. The next time you need to deploy a new VM, you can just create the VM first and choose to attach a hard drive later.

9. Copy the “Server2019DataCenterGen1.vhdx” to the New VM folder, rename it to the name of the new VM so that you can identify the vhdx file easily. 
10. Go back to the settings of this new VM and go to IDE Controller 0 to add a new Hard drive.  Browse to the location of the vhdx that you just copied in step 9.

11. Finished up the settings and start up the VM.  When it boots to windows, you will have a new windows machine as if you just install the OS, ran windows updates and installed the windows features of you choice. 

This is going to save you a lot of time in the long run!