If TaskManger has been Disabled it can be due to various reasons,due to Viruses,Malware and Spywares also,Take a look how to solve this Probelm which Involves two Solutios.
Sol1:By applying windows Group Policy Editor
- Click Start button click Run and Type Gpedit.msc Navigate to User Configuration\Administrative Templates\System\Ctrl+Alt+Del Options\Remove Task Manger
- Double Click Remove Task Manager and set it to Not Configured
Sol2:By Using Registry Editor
- Star Run and Type Regedit and Click o.k
- Navigate to HKEY_CURRENT_USER\Software\Microsoft\Windows current Version\Policies\System
- In the Right pane delete Value DisableTask mgr
- Close Registry Editor.
Note: Regediting is Dangerous be Sure to make a Backup of your Registry