Disabling Alt+Tab functionality entirely in Windows is generally not recommended, as it's a core part of the user interface. However, depending on your specific goal, here are several approaches:
1. Using Group Policy Editor (*) - Pro/Enterprise Editions Only
- Open Group Policy Editor: Press Win + R, type `*`, and press Enter.
- Navigate to the setting: Go to User Configuration > Administrative Templates > Windows Components > File Explorer.
- Find the setting: Look for "Turn off Windows+Tab hotkeys" and "Turn off Windows+Ctrl+Tab hotkeys."
- Enable the setting: Double-click each setting, choose "Enabled," and click OK.
2. Registry Editor (regedit) - All Editions (Use with Caution)
Warning: Incorrectly modifying the registry can cause system instability. Back up your registry before proceeding.
- Open Registry Editor: Press Win + R, type `regedit`, and press Enter.
- Navigate to the key: Go to `HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionPoliciesExplorer`. If the `Explorer` key doesn't exist, create it.
- Create a new DWORD value: Right-click in the right pane, select New > DWORD (32-bit) Value.
- Name the value: Name it `NoWinKeys`.
- Set the value data: Double-click `NoWinKeys`, and set the Value data to `1`.
This method disables Win+Tab, which includes the Alt+Tab functionality in newer Windows versions. It may also disable other Win+Key combinations.

3. Using AutoHotkey (Third-Party Software)
- Install AutoHotkey: Download and install AutoHotkey from the official website.
- Create a new AutoHotkey script: Right-click on your desktop, select New > AutoHotkey Script.
- Edit the script: Right-click the script file and select "Edit Script."
- Add the following lines:
!Tab::Return
- Save the script: Save the file with a `.ahk` extension.
- Run the script: Double-click the script file to run it. It will run in the system tray.
This script remaps Alt+Tab to do nothing. The exclamation point (!) represents the Alt key.
4. Disable Task Switching with a Specific Application (AutoHotkey Example)
If you only want to disable Alt+Tab for a specific application:
- Determine the application's window title: Run the application. Right-click the AutoHotkey icon in the system tray and select "Window Spy." Note the window title.
- Modify the AutoHotkey script:
#IfWinActive, YourWindowTitle ; Replace YourWindowTitle
!Tab::Return
#IfWinActive
- Replace `YourWindowTitle` with the actual window title of the application.
- Save and run the script.
Important Considerations:

- These methods might affect other applications or system functions.
- Third-party software like AutoHotkey requires installation and may have security implications. Download only from trusted sources.
- Test thoroughly after implementing any of these methods.
- To revert changes made via the registry, delete the `NoWinKeys` value or set it back to `0`. For Group Policy, set the setting back to "Not Configured" or "Disabled." For AutoHotkey, close the script.