How do I kill smc.exe (Symantec Endpoint Protection)wa

Ask your IT Department to set up your PC / SEP properly. I have it running on my Thinkpad and on a number of client machines. It uses very little resource normally and does not impede any other application. So either the setup is not optimal for you or there is some thing else wrong. One thing to check is to delete start up scans. Since SEP does real time scanning, start up scans are generally not necessary and slow down start up (but not later operation).
... Thinkpads_User

Symantec has a tamper protection that prevents other process (and users) to kill main processes, like smc.exe. It would be very dificult to kill smc.exe - better way is what thinkpad_user wrote - SEP doesn't use so much resources and is CPU friendly...

Vladimir

This is generally not possible by design. However, you may be able to disable it temporarily by finding the symantec icon in the system tray(bottom left corner of your screen), right-clicking and going to disable. This usually works for me and may work for you if they havent disabled this.

Thanks everyone. But it sounds no one has provided me what I asked for: a way to kill smc.exe so that it stays killed. I'd even settle for someone telling me which process is restarting smc.exe -- so then I could focus on how to kill it.

Asking my corp IT dept to do something about it is a non-starter.

The product you are using is a Corporate Enterprise tool. Why is asking them a non-starter. I help my own clients with this all the time. There is something wrong with your installation, and I don't think your method of approach (user killing processes) will solve anything in this case.
... Thinkpads_User

I pay for access to Expert's exchange for direct answer's to the technical questions I pose; not unsolicited recommendations for how I should do my job.

I do not think my post should cause such a response, but this one might.

The direct answer to your question is that SEP is broken on your machine. No if, ands, or buts. SEP does not run this way properly set up, So completely remove it, restart and start again. I do hope that will fix it for you.

... Thinkpads_User

My question was intentionally very specific. I did not ask "how do I fix SEP". I don't want to know how to fix it because I don't have the authority to do anything to it and I don't want to deal with my IT dept getting around to fixing it.

I asked how to kill a particular process so that it would not be restarted by a another watchdog process. So far, no answer.