Enable "Task Manager Has been disabled by your administrator"

Method 1:

1.Go to Run(CTRL + R) and type " gpedit.msc " as shown in the figure.

2. Now you have to go to this path

Now

Double-click Prevent access to registry editing tools and Set it as Not Configured.

Important: If it's already set to Not Configured, set it to Enabled and click Apply. Then repeat the steps and revert the setting back to Not Configured. This removes the registry based policy

if set already

Method 2:

Click Start, then click Run, type in regedit, and click on OK.

Expand these registry keys in turn:

HKEY_CURRENT_USER->Software->Microsoft->Windows->CurrentVersion->Policies-System

Now delete the key that is shown in the figure.That the end and you should be able to see the Task Manager right infront.