Task manager in your system is disabled by virus? To remove the virus you have to first make the virus not to run. The virus disables registry editor, and MSConfig also along with task manager. So, you can't able to stop the virus from loading with the windows.
You can download Process Explorer and use this utility to view and kill the processes. It offers more features than default task manager bundled with Windows.
If you like your old Task Manger you can enable it by changing options in the Group Policy Editor.
Go to Windows > Run > gpEdit.msc or you can find this in Control Panel > Administrative Tools.
Go to User Configuration > Administrative Templates > System > Ctrl+Alt+Del Options > Remove Task Manger. Disable this option. Now you can see Task Manger option enabled.
Disabling auto play
Important steps when cleaning virus