How can I change system C: drive?

I have a VHDX which I sometimes boot from and sometimes use as a VM in Hyper V. It has Windows installed on the default C: drive. This is somewhat confusing as the C: may be the original C: drive or the VHDX C: drive (with the original C: drive renamed to H: in my case). I want C: to always be the native boot and T: (for example) to always be the boot for the VHDX. Can I change the VHDX...