Watch the video:
Timestamps:
0:00 - Explanation
0:12 - Adding a new drive to Hyper-V Virtual Machine
1:05 - Fix possible virtual machine boot loop
2:00 - Activate/Partition new virtual drive
Need to add another drive to test something, or do you want to import existing virtual drives, physical drives or other media? This video shows you everything you need to know about adding more storage to a virtual machine in Hyper-V.
Stuck on VM Bootloop? Fix: https://hub.tcno.co/windows/hyperv/fix-flashing-restarting-stopping/
Read this guide instead, or get more info: https://hub.tcno.co/windows/hyperv/add-vhd/