I need to know if it's possible to instantly shut down pc , so it's same speed as if I plugged it out of the wall. I'm using windows 10.
What you want is a system crash! Did you know that there is a BSOD error code 0x000000E2 (MANUALLY_INITIATED_CRASH) just for this sort of thing? It's typically caused by a specific combination of keys for debugging drivers and such, but you too can cause one via the handy "NotMyFault" utility from Sysinternals! And since Sysinternals is a MS subsidiary, it's even (kinda) ironic.
Grab that, put it somewhere, and do
NotMyFault.exe /bugcheck 0xE2. (Elevation required, obviously.)
In my application, I need to quicky wipe the RAM to destroy cryptographic keys, so I set Windows to reboot immediately after a BSOD. This causes the BIOS to reinitialize everything, and on any modern machine, zeroes the RAM.
There is known two easy/quick shortcuts for the shutdown, but, do not know any good instant one.
A. Command shutdown -s
B. Pressing the power switch 1sec.
And, risky ones
C. Pressing the power switch 6sec.
D. Cut the power.
Edit: OK, agree, the @MrNerdHair answer NotMyFault 0xE2 is the best one, and I tested it. Just for note, for me it caused two slight problems, Wi-Fi connection device did disappear from the Device Manager totally, and TeamViewer 11 got crippled as the machine got given an untrusted state, but both problems were anyway quite easily repaired.