How to Fix “Task Manager has been Disabled by your Administrator”

Recently i installed windows 8 in my older laptop, i found that when i press CTRL+ALT+DEL key, i can't find the task manager. That's a new problem for me, newbie of Windows 8 users. I tried to open Task Manager by right click the task bar, but "Task Manager" option has been grayed out. I even tried to run it by typing "taskmgr" in RUN dialog box, Windows shows following error message: Task Manager has been disabled by your administrator. So here comes the pain when u intended to close some of the non resposive program/apps.
To fix it,
1. Type regedit in RUN dialog box or Start Menu Search box and press Enter. It'll open Registry Editor.
2. Now go to following keys one by one:
    HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System
    HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\System
    HKEY_USERS\.default\Software\Microsoft\Windows\CurrentVersion\Policies\System
look for a DWORD value "DisableTaskMgr" in right-side pane. If you find it, delete it.
3. That's it. Now Task Manager is back in action!

**If Registry editor is also disabled, then please follow instructions below:
1. Type gpedit.msc in RUN dialog box and go to: User Configuration -> Administrative Templates -> System
in right-side pane, set "Prevent access to Registry editing tools" to either Not Configured or Disabled.
2. Just type following in RUN dialog box and press :
    REG add HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System /v DisableRegistryTools /t REG_DWORD /d 0 /f
Now Registry Editor is back in action too!