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On one of the Windows XP machines I use regularly, there is a process that starts up periodically. I'd like to be able to kill the process – sometimes – because it occasionally runs when I'm busy doing something machine-intensive.

I've already tried dropping the process priority to "Idle" to mitigate the effects, but it isn't the CPU that's the problem. Rather, the process is very disk-intensive and no matter the process priority, it still causes significant disk thrashing when running, impacting everything else I'm doing at the time.

Using Process Explorer, I can find the process, right-click, and choose Kill Process, but I always get the message "Error terminating process: Access is denied."

This is not an operating system process, but third-party software. What might that process be doing to prevent itself from being terminated?

How can I kill such a process? Is there a way for me to modify the process's security or access control list (ACL) somewhere, using Process Explorer or another tool, so that I can effectively kill it?

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@quack quixote: Thanks, but none of those questions deal with the "Access denied" issue central to this question. I'm also asking if there's a way to modify the process security/ACL, and I don't see those questions asking that either. – Chris W. Rea May 7 '10 at 0:34
Though I do see .. very close, but no cigar; I'm asking re: XP x86, not Win7 x64. – Chris W. Rea May 7 '10 at 0:38
Can you tell us the process name? – Jet Mar 7 '14 at 19:13
at 16:44 /Interactive taskmgr.exe

This would add a job to the scheduler to run the taskmgr.exe at 16:44. Select your time about 1 minute in the future from current time. The taskmgr.exe would run with the System account which has additional privileges. See if it works.

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Running interactive tasks is dangerous. – kinokijuf Nov 17 '11 at 19:41
@kinokijuf , dangerous but not in this case. Registry is dangerous too... ;) – Jet Mar 7 '14 at 19:06

The process could be starting with the SeShutdownPrivilege set to Deny (or not set to Allow) for you or the group you're in.

Fire up procexp.exe, find the process, right-click --> Properties --> Security tab --> Permissions button. You may need to run procexp.exe elevated to see anything.

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up vote 1 down vote accepted

Looks like I'm able to kill the process in question using Process Hacker, which, coincidentally, I learned about today from a SuperUser Community Promotion Ad:

Process Hacker: more than you ever wanted from Process Explorer.

One of the features listed is "powerful process termination". From the project page:

Process Hacker is a free and open source process viewer and memory editor with unique features such as powerful process termination. It can show services, processes and their threads, modules, handles and memory regions. [emphasis mine]

While I don't intend for to replace Process Explorer, this is certainly a complementary new tool worth keeping around, and I'm curious to learn more about it.

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taskkill /f will do it!

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Thanks for the suggestion, but here was the result: ERROR: The process with PID nnnn could not be terminated. Reason: Access is denied. – Chris W. Rea May 6 '10 at 17:35
and you had the /f typically I have cygwin installed and a kill -9 works everytime so I was hoping that taskkill /f would to this! if you do sc /queryex processname you should see the reason for not being able to kill the process. – user33788 May 6 '10 at 18:52
I also have cygwin installed. "kill -9 nnnn" reports: bash: kill: (nnnn) - No such process ... I don't even think cygwin's kill sees this process since it isn't a cygwin process. "ps -ef" only lists bash and ps. – Chris W. Rea May 6 '10 at 19:55
how about wmic process where "processid='xxxx'" delete – user33788 May 6 '10 at 20:31

What is the software? Sounds like it's running as a service. You'll get that error when you try to kill a process (from Task Manager or Process Explorer) that is running as a services.

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