"End Process" on the Processes-Tab calls TerminateProcess which is the most ultimate way Windows knows to kill a process.

If it doesn't go away, it's currently locked waiting on some kernel resource (probably a buggy driver) and there is nothing (short of a reboot) you could do to make the process go away.

Have a look at this blog-entry from wayback when: http://blogs.technet.com/markrussinovich/archive/2005/08/17/unkillable-processes.aspx

Unix based systems like Linux also have that problem where processes could survive a kill -9 if they are in what's known as "Uninterruptible sleep" (shown by top and ps as state D) at which point the processes sleep so well that they can't process incoming signals (which is what kill does - sending signals).

Normally, Uninterruptible sleep should not last long, but as under Windows, broken drivers or broken userpace programs (vfork without exec) can end up sleeping in D forever.

I had a similar problem with multiple instances of conhost.exe that I could not terminate with taskkill, even giving the exact pid. I always got the same error, saying that there are no instances of the task.

So I did what Pimp Juice IT suggested in a comment above using the following command, which successfully killed all conhost.exe at once.

wmic process where name="conhost.exe" call terminate

You can try with :

TASKKILL /F /IM "notepad.exe"

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you must kill child process too if any spawned to kill successfully your process

taskkill /IM "process_name" /T /F

/T = kills child process

/F = forceful termination of your process

Reminder: in a batch file you will need to use the double "%%" instead a single

FOR /F "usebackq tokens=2 skip=2" %i IN (`tasklist /m winsta.dll`) DO taskkill /PID %i

For Windows XP, Vista, 7:

Basic options overview:

If you know the name:

taskkill /IM (program).exe

If you know the PID:

taskkill /PID ###

Kill all processes by one user (Quinn in this instance):

taskkill /FI "USERNAME eq Quinn"

Taskkill options:

• /F - force kill with no confirmation
• /IM - by program name
• /PID - by process ID number

• /FI - by filter:

  Filter Name     Valid Operators     Valid Value(s)
  -----------     ---------------     --------------
  
  STATUS          eq ne               RUNNING | NOT RESPONDING
  IMAGENAME       eq ne               Image name
  PID             eq ne gt lt ge le   PID value
  SESSION         eq ne gt lt ge le   Session number
  CPUTIME         eq ne gt lt ge le   CPU time in the format of hh:mm:ss.
  MEMUSAGE        eq ne gt lt ge le   Memory usage in KB
  USERNAME        eq ne               User name in [domain\]user format
  MODULES         eq ne               DLL name
  SERVICES        eq ne               Service name
  WINDOWTITLE     eq ne               Window title
  

Modifiers:

• eq: equals
• ne: not equal
• gt: greater than
• lt: less than
• gt: greater than or equal
• le: less than or equal