How to make a program non-closable?

Question

WPF

The user is sitting as a normal user in Windows XP/7. Once every 30 minutes, the program asks him to enter a captcha to check for a user at the workplace, the result is sent to a remote server.
The user should be deprived of the opportunity to close the program, remove the program. remove the program from startup. That is, it should always be active. What is the best way to do this?
I have several suggestions:
1) Make active N instances of the program checking very often for the presence of their copies in the system. If one of the processes is closed, another process will immediately start. Most likely, the user will be able to bypass this protection if he closes all processes in bat at once, or simply prohibits the process from starting (if it is possible to do this from under user acc).
2) Somehow they will be introduced into other processes, it is already more like a virus. Possible conflicts with antivirus.
3) Write Windows Services that will support life in my exe
Please tell me which way to dig?

Answer 1

To prevent the user from closing the program, it is enough to take away his rights.
A banal task in the scheduler that will run the desired program at a certain time.
A simple user has no rights to edit tasks.

Answer 2

And what's the problem? If the program does not work - consider that the user is not at the computer. Well, as a tracker for the same Upwork, it works.
This is if the goal is to make the user be interested in generating activity on the computer. If the goal is different - see Artem's answer - it is suitable if you administer user machines. If the machines are administered by the users themselves (that is, you do not have exclusive rights to them), then, IMHO, there is no reliable method by definition. Secure boot, boot from another media, etc.

Answer 3

1) procexp.exe - the process will be frozen, and two will stop at once.
3) Set permissions on the service, the user will not be able to start or stop.
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