Comment by Bender

And before that and before Trucrypt many used Jetico BestCrypt [1] not free... It can pretend the OS disk is invalid until a passphrase is typed. Only useful to fool smash-and-grab trash level thieves but I found it entertaining.

Either way once the Windows OS volume is unlocked it's all moot. There are many other ways to access ones machine remotely such as pushing a targeted update to the specific machine OS agnostic but easiest on Windows as Windows update fires off all the time despite patches being on a specific Tuesday. This method applies to phones as well, beyond the JTAG encryption bypass at power-up. Then a gag order is applied.

[1] - https://jetico.com/data-encryption/encrypt-hard-drives-bestc...