[Blind-sysadmins] Accessible encryption windows hard/ssd/thumb drives at use and at rest?

Hello, I just dodged a big bullet, which could have had identity-stealing implications if I hadn't got lucky. That being the case I'm looking for accessible encryption methods, free is best, for windows drives, complete drives, hdd/ssd/m.2/USB/sd/if I plug it in it's a drive. I'm needing it to be accessible when the system is booted up in windows, but if the machine is shut down or powered off, basically if the drive is removed it's at-rest encryption so that if someone were to pull it out of a computer (which happened) they would not be able to read anything on it, so I'd be out a drive and not the valuable data that goes with it. Thanks. Dave.