CTRL + ALT + DEL is used to open the security options window. The options on the page allow users to change their password, log off, shut down or restart the system, and log into the Task Manager. Otherwise, all these options are available in the system, but the purpose of the security options window is to access these emergency options when the computer freezes and nothing else is working.
If the security options window stops working, it may not be an immediate emergency if the system is working properly, but it should be fixed as soon as possible. In case we lose access to the security options window when needed, the only way to deal with a frozen system would be to shut it down, which could damage the hardware or lead to data loss.
The causes of the problem can be many. A known cause is malware affecting the system, even the keyboard may be faulty.
We will try the following troubleshooting step by step to fix the problem:
Note: - If you are looking to open Task Manager and can't find it in CTRL + ALT + DEL screen, you can try to press CTRL + Shift + Esc together from the keyboard to open the task manager immediately. Also, some users have reported that if they have Microsoft HPC Pack on their PC, removing Microsoft HPC Pack fixes this problem immediately.
Solution 1] Through the registry editor
1. close regedit in the Windows 10 search box and click the registry editor icon to open Registry Editor.
2. Now go to the following path in the registry editor.
HKEY_CURRENT_USER Software Microsoft Windows CurrentVersion Policies
3. Now check if there is a key called System when you expand the criteria. If it doesn't exist, right-click the criteria and create a new key called System.
4. Now on the right side, right click and choose New> Dword (32-bit) Value Named As DisableTaskMgr.
5. Now double click DisableTaskMgr and change the value data to 0.
6. Now, close the registry editor window e start again PERSONAL COMPUTER.
Solution 2] - Check your keyboard / language
1. Press Tasto Windows + I together from the keyboard to open the settings.
2. Click Time and language.
3. Click language in the menu on the left.
4. Check yours language of the list.
5. If the correct language is not displayed, click Add a preferred language to add the required language on your PC.
6. Now, when the correct language has been included in the language list, simply click on the desired language and then click the up arrow button to move it up.
Solution 3] Check the keyboard
Two good ways to check if the keys are working would be to check the keys for other functions and temporarily replace the keyboard. If in any case we find the bad keys, we could try to update the keyboard drivers.
Update the keyboard drivers and reboot the system.
If that doesn't work, you can try replacing the keyboard or using an external USB keyboard for now.
Solution 4] Check your system for malware
Malicious software and viruses may affect your system in a way that hinders security procedures if they damage your system. They are usually written like this. Therefore, it is necessary to scan and remove the malware from the system. Use your antivirus program to scan the system and remove malware from the system.
Solution 5] System Restore
If the above solutions don't work, you can try to restore the system as mentioned here.
I hope this helps!