How to protect a Dell laptop if lost?

Question

Dell

I found out about the existence of the site bios-pw.org - I checked it, and now it makes no sense for me to set the admin password for the BIOS.
The password for Windows is thrown off by a flash drive, as you remember.
How, then, to protect it, so that in case of loss it would be impossible to get to the data in a simple way?

Answer 1

bitlocker

Answer 2

or good old truecrypt