You can try some of the methods here: https://service.mcafee.com/webcenter/portal/cp/home/articleview?locale=en-US&articleId=TS101587
If those do not help, contact mcafee support: https://service.mcafee.com/webcenter/portal/cp/home/contact
I found nothing useful in this material...
I need something concrete to solve my problem
Well, if there were something to provide over a public forum, then the anti-theft would be pretty worthless, right?
Sorry, but you will have to contact mcafee support, or figure out how you locked it.
In fact I din"t lock it
I opened my laptop and appeared in this way...
Ok, I understand what you are saying.
But, look at it this way:
We have no idea who you are or if the laptop is actually yours. To provide an unlock procedure, if one were available, cannot be done because we cannot verify if you are the actual owner of the laptop. If someone were to steal your laptop, and come to a public forum, and were so easily provided an unlock procedure, you would not be very happy.
There is nothing this forum can do to help you. And, as far as I know, there may be nothing you can do to recover this laptop.
Now, you did have a back-up of your data, correct? Rebuild the laptop, load your back-up, and you are good to go.
If you do not have a backup of your data, and cannot figure out how your laptop got locked, or who locked it, you will not have a very good start to 2018.
Sorry, but that is the reality of the situation.