Well, this situation might never arise when you need to Disable your Task manager. But more commonly it happens because of a virus attack. Viruses do disable the Task Manager. Now they do so by editing the Registry values. Even if you remove the viruses, the registry changes will remain and thy will continue to effect your system, until you correct them. This is easy and I will let you know how this can be done with just a small change in Registry. Here’s what you need to do.

1. Go to Start –> Run, and open Regedit.
2. Go to HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System
3. If you are infected by a Virus then you will see a Dword Value “DisableTaskMgr“, if not, then create this new value.
4. To Enable it, give a value of “0“, and to Disable it, give it a value of “1“

This is a very simple method by which Task manager can be Enabled/ Disabled. Apart from that, if you are in a network, and want to disable Task manager for a user, then you need to change the Computer Policies