At this point, it seems like even Microsoft has given up on Cortana. Sure, the digital assistant is built into Windows 10, and its search box appears in the lower left corner of the taskbar by default, but the OS now allows users to access Alexa, a tacit admission by the company that it has lost the assistant race.
If you're just plain tired of Cortana, you can disable her completely by following the steps below. However, with Cortana disabled, you can't use any of its features, including natural language file search (ex: "show me my pictures from last weekend") and reminders, nor can you access Alexa from your PC.
1. Open the Windows Registry Editor. You can get there by typing "reged" into the search box.
2. Navigate to the registry key Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows
3. Create a new key named "Windows Search" by right-clicking and selecting New->Key then renaming the folder it creates to "Windows Search." If Windows Search already exists, navigate to it.
4. Create a new DWORD (32-bit) Value named "AllowCortana" in the Windows Search Key. You can do this by right-clicking and selecting New->DWORD (32-bit) value, then renaming it to "AllowCortana".
By default, AllowCortana is set to 0, which means off. If you set it to 1, then Cortana will be enabled.
5. Reboot your computer.
You should see a "Type here to search" box where Cortana's box used to be. You can use this box to search your local files and apps, as well as the web (via Bing).
Disabling Web Search
Even with Cortana off, the search box will still pull up web results, which can be slow and annoying. To disable web search:
1. Navigate to Computer\HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Search in the registry editor.
2. Create a new DWORD (32-bit) Value named "BigSearchEnabled." If it already exists, set it to 0.
3. Log out and in again or reboot your PC.
Now, when use the search box, the computer's message won't mention web results like it did before.