So i need data from one pc in school and i don't know password(windows 8.1 newest update) so can i make usb bootable linux distro.. Like plug, boot and use not try before install.,like use operating system from my usb not hdd. Please help.
And can i use kali linux to find out some password's? I just need usb linux in simple words

Per the LinuxQuestions rules:

I am so sorry! I will update my question to look normal and not aboutsick information stealing

No matter how you rewrite the question the intent of breaking into a school PC that you do not have access to is still the same. I would assume this goes against the school rules too.

Ok i will go from school to home and change it

Ok and if i use my bootable usb to recover images and.doc files from demaged pc? I think it will be not against law and rules. And still i want to play games like cs1.6 and Half life 1 on linux, but don't install them on hdd and don't use hdd, but use usb flash drive to install on and play from linux in flash drive..
My point is to make bootable usb with linux(with plug, boot and use thing) to play games from any pc(for 1 thing:my friend have high tech pc and he can't play old games and my usb can save that problem and i can help to recover data from damaged windows) please help! And don't think i will go outside from law i don't want to f*+k with my life and ruin my life from stupid old 4gb usb flash drive.

You might have to do an online search for your games because a lot of them are written to only run on windows. Some will run on Linux, some better than others. I would just search 'games on Linux' and see what you get. Also, if you are going to be using a Live CD on a flash drive, it will be read-only and you won't be able to install anything or save on reboot. You can create a persistent flash drive and then install software and save changes. I think a 4GB flash will be too small to do much with.