Lock PC during Boot. ???

Hello,
can anyone suggest me some PC locking software. I heard about a program able to lock a pc during a bootup, and it would require a pendrive to start the pc. It is not a freeware, i had read about here in Wildersecurity few years back, then i didn't find it important. Their are tonns of those that can lock from withing the pc, when left idle, not that.
I want that particular one where a user is required to insert a pendrive and provide a password i guess. Can someone help me out.
Googling is just a waste of time.

 

A simple way to do this would be to encrypt the boot drive with TrueCrypt and set a password on the encrypted volume. Then you wouldn't have to worry about losing a flash drive (just forgetting the password ) I've heard of specific applications requiring USB drives/keys to work, but not at the BIOS level.

 

What do you mean by lock pc during boot please?
Mrk

 

i mean, the default mbr of the windows would be rewritten, that would make this locking software to run first and a user should provide a password, after inserting a usb, then the pc would read the default boot record : i had heard of it here in wildersecurity years back.