I found out the hard way. One morning, I tried to start up the unit. The operating system wanted me to enter the BitLocker password.  As I had never set up the BitLocker feature, I had no idea what it was. Without it, you can only reformat the hard drive. All your data will be lost. Absolutely no way to recover it.The original purchaser must have set up a password, then returned the pc with this time bomb in it.