Thanks for posting!
As there is generally no Internet access from BIOS and as TeamViewer cannot be running on the remote computer while in BIOS, unfortunately it is not possible to remotely control a device and access that devices BIOS as this is a restriction of remote control software.
I am sorry for the disappointment.
Unfortunately we have no ability to implement this feature.
This isn't a case of us not developing the feature, it just isn't possible. It would be like trying to provide software to connect to a computer that wasn't connected to a network in any way, it just isn't something that software is capable of doing as there is no software running at the BIOS.
I am sorry for the dissapointment.
Luckily I've found that spark for you here. You can try the software [Removed by Moderator as per community Guidelines - TeamViewer only please]
The technology you need is called KVM over IP (out of band service). Basically it is a hardware solution that can work the keyboard, mouse and monitor through the internet even if the computer's Operating system is locked up or you need to flash update the bios or just make bios level changes as if you were sitting right in front of the keyboard locally but really are half way around the world.
I once had a isa card setup that did this, but it stopped working once the pentium era came about and at that time my remote needs were not that extreme, but I find myself once again searching for the best cost best solution for moder servers..
So far I found that [Removed by Moderator as per community Guidelines - TeamViewer only please] will work if you have a bunch of remote pc's to manage at this level.
It would be possible with say a raspberry pi, captures the video port and relays it back along with mouse keyboard instrutctions. but that would require software support that does not exist.