For whatever reason, Microsoft does not want you to remove Cortana completely in Windows 10. Previously, you used to be able to toggle Cortana on and off in Windows 10, but Microsoft decided to remove that option in the Windows 10 Anniversary Update.
The only way you can remove Cortana now is via an edit in the Windows Registry or as a group policy setting for Windows 10 Pro and Enterprise users. By removing Cortana in Windows 10, the Cortana box is transformed into a “Search Windows” tool for local application and file searches on your Windows 10 PC. By default, Cortana only uses Bing for search in Windows 10 and oftentimes automatically opens up Microsoft Edge to browse the internet.
Microsoft has continued to restrict Cortana’s role in Windows 10. So if you do not need Cortana anymore, why is Microsoft forcing Windows 10 users to still use Cortana? If you have Windows 10 Home and you want to completely remove Cortana, you will need to perform a Windows Registry edit. Here is what you need to do to completely remove Cortana from Windows 10.
Turn off Cortana in Registry Editor for Windows 10 Home
1. Open the Run dialog box by using the Windows Key + R keyboard shortcut.
2. Type regedit in the Run dialog box and press Enter to open the Registry Editor.
3. Choose Yes in the User Account Control (UAC) dialog button that pops up. The Registry Editor will open. Copy and paste the following path in the Registry Editor navigation pane:
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Windows Search
4. If you don’t see the Windows Search folder, you need to create a new one by right-clicking the Windows main folder above and choosing New > Key. Rename the new Key (folder), “Windows Search.”
5. Right-click the “Windows Search” key (folder) in the left pane and select New > DWORD (32-bit) Value. Name the value AllowCortana.
6. If you already have the Windows Search key (folder) and the AllowCortana value, double-click AllowCortana and make sure that the hexadecimal base value data is set to 0. 
7. Click OK when you are finished. You can now close the Registry Editor and restart your Windows 10 PC for the changes to take effect.
Turn off Cortana in Group Policy Editor for Windows 10 Pro and Enterprise
The easiest way for Windows 10 Pro and Enterprise users to remove Cortana is e Cortana is via the Local Group Policy Editor. Be sure that you check with your IT admin first before you go ahead and make any edits.
1. Open the Run dialog box by using the Windows Key + R keyboard shortcut.
2. Type gpedit.msc in the Run dialog box and click OK to open the Local Group Policy Editor.
3. When the Local Group Policy Editor opens, go to the following path:
Computer Configuration > Administrative Templates > Windows Components > Search
4. Locate the Allow Cortana setting in the right side and double-click it.
5. Set the Allow Cortana setting to “Disabled” and choose OK.
6. Close the Local Group Policy Editor and restart your Windows 10 PC for the changes to take effect.
Once your computer restarts, Cortana will be removed from your Windows 10 PC. Your Cortana search box will be replaced by a Windows Search box that you can use to search your local Windows 10 PC and the web, but Cortana is gone.
You may want to take it another step further and go to your Microsoft account and delete everything that Cortana knows about you too.
Do still use Cortana in Windows 10? Let us know in the comments.
