1, run gpedit.msc open Group Policy, followed by open the “User Configuration → Administrative Templates → System → Ctrl-alt-del option, double-click “Delete Task Manager”, the “disabled” Check it.
2, Use anti-virus software to scan the whole system,
3, if it can not be used, and must be used, it is recommended or reinstall the system.
There are many ways to open the Task Manager, but the operations are very complicated. More than a few ways to meet the daily needs of the computer network in this no longer repeat.