This usually happens because of a virus infection. Of Course, try to remove the virus first since any changes that you make will be reverted by the virus that may still be on the computer.
However, if you are pretty sure that the virus infection has been eliminated then go ahead and try these methods below:
Method 1:
•Click Start, Run and type Regedit.exe
•Navigate to the following branch:
HKEY_CURRENT_USER \ Software \ Microsoft \ Windows \ CurrentVersion \ Policies\ System
•In the right-pane, delete the value named DisableTaskMgr
•Close Regedit.exe
Method 2:
•Click Start, Run, type gpedit.msc and click OK.
•Navigate to this branch:
User Configuration / Administrative Templates / System / Ctrl+Alt+Delete Options / Remove Task Manager
•Double-click the Remove Task Manager option.
•Set the policy to Not Configured.
Method3: Change the Task Manager Option through the Run line
- Click on Start, Run and type the following command exactly and press Enter
REG add HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System /v DisableTaskMgr /t REG_DWORD /d 0 /f
Method 4: Change Task Manager through a Registry REG file
- Click on Start, Run, and type Notepad and press Enter
- Copy and paste the information between the dotted lines into Notepad and save it to your desktop as taskmanager.reg
————————————
Windows Registry Editor Version 5.00
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System]
“DisableTaskMgr”=dword:00000000
————————————-
3. Double click on the taskmanager.reg file to enter the information into the Windows registry
Method 5: Delete the restriction in the registry manually
- Click on Start, Run, and type REGEDIT and press Enter
- Navigate to the following branch
HKEY_CURRENT_USER \ Software \ Microsoft \ Windows \ CurrentVersion \ Policies\ System
- In the right pane, find and delete the value named DisableTaskMgr
- Close the registry editor
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