Explanation:
Box 1: Shut down VM1.
Box 2: Modify the virtual switch settings of the legacy network adapter.
Box 3: Modify the BIOS settings of VM1.
Note:
Step 1: The VM need to be shutdown first.
Step 2:
1. You need to create a virtual switch. This is needed for the Virtual Machine to be able to communicate with the network. If you already have created a virtual machine for your network, you can skip this step. Start by right-clicking the Hyper-V host in Hyper-V Manager and selecting "Virtual Switch Manager".
2. Create a new Virtual Switch. Select "External", which is similar to "Bridged" if you're used to other virtualization software.
3. Give the new Virtual Switch a name.
4. By default, there is only a "Standard Network Adapter" installed on the Virtual Machine, but for PXE functionality you will need to add a "Legacy Network Adapter".
5 . Go to the "Legacy Network Adapter" that you just added and specify that it should use the Virtual Switch that you just created.
Step 3: you should change the BIOS boot priority to make sure that the Virtual Machine always tries to boot first using the "Legacy Network Adapter". Just select the "Legacy Network Adapter" and move it to the top using the buttons.
Step 4: Start your Virtual Machine and now PXE boot should work.