Problem with virus...... Task manager enabler

If you have any viruses, then you may notice that they affect to  
the task manager and disable it
This is because if we know that there is a virus active in our  
background there’ll be a chance to stop it using task manager.
Disable task manager doing by viruses editing the computer  
registry.
Here how you can fix and get back the Task manager again.

"Method 1":Click Start >> Run >> and type the code below and press  
Enter.
REG add HKCU\Software\Microsoft\Windows\CurrentVersion\Pol  
icies\System /v DisableTaskMgr /t REG

"Method 2":Click Start>> Run>> and type Regedit.exe (open registry  
editor)
Navigate to the HKEY_CURRENT_USER \ Software \ Microsoft \ Windows  
\ CurrentVersion \ Policies\ System .In the right-pane, delete the  
value named DisableTaskMgrClose Registry editor. You may want to  
restart you computer for changes take effect.

"Method 3":Click Start >> Run >> type gpedit.msc (Open Group  
policy editor)