How can I put the computer to sleep from Command Prompt/Run menu?

The methods posted by other people do not work correctly if a computer has hibernation enabled, the computer will not wake on Keyboard or, more importantly, not wake on scheduled task.

One of Microsoft's Sysinternals tool is PsShutdown using the command psshutdown -d -t 0 it will correctly sleep, not hibernate, a computer

The command rundll32.exe powrprof.dll,SetSuspendState 0,1,0 for sleep is correct - however, it will hibernate instead of sleep if you don't turn the hibernation off.

Here's how to do that:

Go to the Start Menu and open an elevated Command Prompt by typing cmd.exe, right clicking and choosing Run as administrator. Type the following command:

powercfg -hibernate off

NirCmd workes on Windows 8 (I assume it also works with Windows 7) → http://www.nirsoft.net/utils/nircmd.html
The command is standby, but it puts the computer to sleep.

nircmd.exe standby

If you have hybrid sleep enabled, it will work; i.e., it puts the computer to sleep and copies the memory to disk in case of power loss.

See the free utility of Wizmo, which can do very many things.
The command you're looking for is probably:

wizmo standby

You can initiate the suspend or hibernate options from the command line as specified below and referenced in this article.

%windir%\System32\rundll32.exe powrprof.dll,SetSuspendState

If your computer is set to allow hibernation then the above command will initiate hibernation. If the hibernation feature is disabled, then it will enter the standby state. As other users have answered previously, shutdown.exe /? will provide many shutdown options.

I have created a shortcut for rundll32.exe powrprof.dll,SetSuspendState 0,1,0 (also tried with 0,0,0), but running the shortcut seemed to put my PC into hibernation. I could not wake up the PC using the keyboard; I had to press the power button, and the PC showed the mainboard post messages, etc.

After reading the Windows API document, I created a very simple programme with just 3 lines of typing. I have uploaded the executable I compiled to this page (click the "SleepTest.exe"), but this file could be deleted after a while (this is a free file hosting site that I just found by a quick Google search).

If you do not trust me (which is totally fine) or the file has been deleted, you can compile the code yourself, Of course. You need to add "PowrProf.lib" to the additional dependencies of the Linker.

#include "stdafx.h"
#include "windows.h" <-- Added this to make it work on Windows.
#include "PowrProf.h" <-- Added this to use the sleep function.

int main()
{
    SetSuspendState(FALSE, FALSE, FALSE); <-- Added this actual call.
    return 0;
}

rundll32.exe powrprof.dll,SetSuspendState 0,1,0 seems to be doing the same thing, but somehow, the programme above did not put the computer into hibernation. I could wake up the PC instantly (no mainboard post messages, etc) by pressing any key on the keyboard.

You must first disable Hibernate in windows and then put the computer in Sleep state. Use following two commands:

powercfg -hibernate off
rundll32.exe powrprof.dll,SetSuspendState 0,1,0

and for doing reverse action, Hibernating the computer, use commands below:

powercfg -hibernate on
rundll32.exe powrprof.dll,SetSuspendState Hibernate

If you have Python (with pywin32) available you can also call that SetSuspendState function directly with:

import ctypes
ctypes.windll.PowrProf.SetSuspendState(0, 1, 0)

This can easily be put into a batch file or a shortcut sorta like:

pythonw -c "import ctypes; ctypes.windll.PowrProf.SetSuspendState(0, 1, 0)"

So then if you don't have your .py files associated to the interpreter you can just double click the link.

The shutdown part of the question is clear for everybody.
shutdown.exe /? shows all choices to shutdown / restart / advanced options boot / firmware boot.

But I see so much bashing thrown around about the Sleep part.
Everybody gets it that rundll32.exe should not be used to call random functions and it just works here for hibernate entirely by coincidence. But that's the nature of Windows - a black box that people have poked around and found hundreds of workarounds to get a job done (shout-out to dostips).

There are so many "proper" solutions proposing external tools, yet I can't seem to find a native (hybrid / pinvoke / whatever) batch script, even if this question has remained active over the years.
So here's my simple power_sleep.bat:

@echo off &mode 32,2 &color cf &title Power Sleep
set "s1=$m='[DllImport ("Powrprof.dll", SetLastError = true)]"
set "s2=static extern bool SetSuspendState(bool hibernate, bool forceCritical, bool disableWakeEvent);"
set "s3=public static void PowerSleep(){ SetSuspendState(false, false, false); }';"
set "s4=add-type -name Import -member $m -namespace Dll; [Dll.Import]::PowerSleep();"
set "ps_powersleep=%s1%%s2%%s3%%s4%" 
call powershell.exe -NoProfile -NonInteractive -NoLogo -ExecutionPolicy Bypass -Command "%ps_powersleep:"=\"%"
exit

It even works as a big one-line command:

powershell.exe -C "$m='[DllImport(\"Powrprof.dll\",SetLastError=true)]static extern bool SetSuspendState(bool hibernate,bool forceCritical,bool disableWakeEvent);public static void PowerSleep(){SetSuspendState(false,false,false); }';add-type -name Import -member $m -namespace Dll; [Dll.Import]::PowerSleep();"

Here's an article on using CLI to shutdown.

Microsoft provides PsTools which gives you CLI shutdown along with other useful tools. You can get that here.

only QUICK SLEEPER works for me (works in Windows 7,8,10).

p.s. source code available here.