Enable / Disable Task Manager in Windows XP Home / Pro

There is a registry hack to enable or disable Windows NT TaskManager. The same registry hack applies to Windows 2000 and Windows XP.

Hive: HKEY_CURRENT_USER
Key: Software\Microsoft\Windows\CurrentVersion\Policies\System
Name: DisableTaskMgr
Type: REG_DWORD
Value: 1=Enablethis key, that is DISABLE TaskManager
Value: 0=Disablethis key, that is Don't Disable, Enable TaskManager

As part of the enhanced management available in Windows 2000 and Windows XP, rather than risking a registry change, as an administrator you can enable or disable Windows 2000 Pro or Windows XP Pro's TaskManager using Group Policy Editor. This can be applied to the local policy. Note: if you are trying to override your organizations group policy, you can't. As soon as you re-authenticate to the domain, the domain or OU Group Policy will rewrite the registry setting. But if the TaskManager was accidently disabled or you need to control this item for a set of standalone boxes this is for you:

Click Start
Click Run
Enter gpedit.msc in the Open box and click OK
In the Group Policy settings window

Select User Configuration
Select Administrative Templates
Select System
Select Ctrl+Alt+Delete options
Select Remove Task Manager
Double-click the Remove Task Manager option

And as I mentioned above, since the policy is Remove Task Manager, by disabling the policy, you are enabling the Task Manager.
Got XP Home - use the registry edit.

how to enable regedit?

Start -> Run -> gpedit.msc -> User Configuration -> Administrative Templates -> System -> Prevent access to registry editing tools -> Right Click Properties -> Disabled