If you're preparing to migrate a VMware virtual machine over to, let's say a KVM-based Type-1 Hypervisor environment, there are several preparation steps that should be undertaken, the first of which will be to change the network adapter from a static IP addresss to a DHCP address, and to remove the VMware Tools. If you forget to remove VMware tools prior to conversion, the converted VM may not boot. If you forget to manipulate the network LAN adapter settings, you could end up with a "ghost" adapter, one that has entries in the Windows registry, but that does not show up in device manager. If you also forgot to change the static IP address to a DHCP address, the static IP could be "trapped" by the ghosted adapter and Windows will give you error messages saying another adapter already has that IP address.
Here's how to "reveal" those ghosted adapters so you can clean up the mess left behind by a hypervisor platform migration.
1. Launch a command prompt as administrator in the VM.
2. Run: set devmgr_show_nonpresent_devices=1 (press enter)
3. Launch Device Manager (devmgr.msc)
4. In Device Manager -> View select "Show Hidden Devices"
5. Scroll down to Network Devices and expand
6. Ghost adapters will be greyed out - right click and Uninstall
7. Select Action -> Scan for Hardware Changes to refresh device list
8. Repeat as necessary until all ghost adapters are removed
Windows OS Hub has a write-up on this process here: https://woshub.com/remove-hidden-ghost-network-adapter-windows/
Interworks has a blog post about the topic here:
https://interworks.com/blog/ijahanshahi/2014/08/21/removing-hidden-device-device-manager/
The official VMware-to-Proxmox conversion instructions are here:
https://pve.proxmox.com/wiki/Migrate_to_Proxmox_VE
Scale Computing has their own SC//Migrate toolkit to make VMware to Scale migrations easy:
https://www.scalecomputing.com/resources/sc-migrate-data-sheet