Re-Enable windows Task Manager, if it has been disabled by Virus, malicious code or such events.

Yeah, you can enable your task manager, whether it has been disabled by the administrator or any types of virus malicious code via the help of registry editor or from the Local Group policy.
Actually, this type of task can be perform by the malicious code like a virus or worm and such types of. So, if you really in trouble and want to enable you task manager, then you can simply follow some of the few steps to enable that bocz task manager is the utility where you can visible your all process activity so its a too much important utility for the windows user.
So, I tell you how can we enable this.

Task Manager : A Task manager is a program used to provide information about the processes and programs running on a computer, as well as the general status of the computer. It can also be used to terminate processes and programs, as well as change the processes priority. In some environments, users can access a task manager by pressing the buttons Control-Alt-Delete or Ctrl+Shift+Esc.
Task managers can display currently running services (processes) as well as those that were stopped. They can display information about the services (such as Process ID and group) if known.

Enable Windows Task Manager: To follow some of the simple steps.

1. Open Run box or press [Win]+[R] and write gpedit.msc

2. A Local and Group policy windows will be open. same as the below screenshot and now follow the path as show in the image.

Local Computer Policy > Use Configuration > Administrative Templates > System > Ctrl + Alt + Del Option.

3. Now see at the right side panel and double click on the Remove Task Manager key. An another windows will be open like this.

so, now if you want to enable task manager just select the Disable option and click on apply and finally Ok.

Note:

For Enable Task manager : select Disable option

For Disable Task Manager : select Enable option

Another Note:

If your task manager disable by some virus and malicious code, then it can be enable from here..but actually the virus code is already running in your windows at that time then task manager may be disable again and again. And you will again show this msg.