Is it really possible to break into a computer that is locked?

Hi,

This is not a question on how to do it, but to clarify if it is possible and if so how to make sure it does not happen.

A family member told me a few days ago that he would have little problem accessing my PC that was locked if he used a small program that that he brought along on a USB.

I have set up all accounts on my computer at home with PIN codes. Would he really be able to access my user on my computer as he claims (or in any other way)?

This is a guy that works with computers so I do not know if he told me this only to scare me or if he would really be capable of doing what he say.

Therefore I ask you guys :)

dalchina said:

Locked as in lock screen? Win key + L?

Yes. I understand that this would leave the computer open and as long as someone has physical access to the computer my files would be accessible to that person. I was under the impression that this PIN code was safe...

I assume there are no quick and easy way of making sure that the computer can only be accessed after entering the correct PIN or password?

Thank you.

I belive this solution is a bit above my skill level...

Is it possible to instead disable some, or all, USB ports?

Cliff S said:

For the really secure minded(when a real threat is present) or paranoid (when no no real threat is present) there is an option in BIOS to use a password to get into BIOS, and to even BOOT the system at all.
Then his USB toy is useless.

Would this password then only be required when the PC is restarted? If I keep the PC running it would not ask for it every time I want to unlock Windows?

Do I understand correct that he would need to restart the computer to use his USB toy and then he will be faced with this BIOS password?

It is not that I fear that he will destroy anything, but this is a funny guy and if he got the chance he would surely take the opportunity and do something (in his mind) strange on my computer. It would be a nice surprise for him if that attempt failed :)