Disable Cortana, and Windows 10 will switch to using local search for everything. But, if you open the Task Manager, you’ll still see “Cortana” running in the background anyway–why is that?

Cortana Is Really Just “SearchUI.exe”

 Whether you have Cortana enabled or not, open the Task Manager and you’ll see a “Cortana” process.

If you right-click Cortana in the Task Manager and select “Go to Details”, you’ll see what’s actually running: A program named “SearchUI.exe”.

If you right-clicked “SearchUI.exe” and selected “Open File Location,” you’d see where SearchUI.exe is located. It’s part of the “Microsoft.Windows.Cortana_cw5n1h2txyewy” application folder in Windows.

This application appears as “Cortana” in the list of running processes so it’s more easily understandable. But it’s actually a smaller tool named SearchUI.exe.

“SearchUI.exe” Is the Windows Search Feature

We decided to disable access to SearchUI.exe so we could check what it actually does. We ended the Cortana task from the Task Manager and then renamed the “Microsoft.Windows.Cortana_cw5n1h2txyewy” folder to something else. After we did, Cortana doesn’t appear to be running in the background–but the Windows Search feature is completely broken.

That’s right: Windows 10’s search feature completely breaks. Clicking the “Search Windows” box on the taskbar or pressing Windows+S on your keyboard does nothing. The search dialog just won’t appear.

Rename the Cortana folder back to its original name and the search dialog suddenly appears normally again.

SearchUI.exe isn’t really Cortana at all, though they are intertwined. “Cortana” is both the name for Microsoft’s online assistant, and the name for all the local search tools built into Windows 10. When you disable Cortana from the registry or group policy, all the online features are disabled–but the local file search tools are left running. Those are technically part of the “Cortana” application, as that’s just how Microsoft has implemented things in Windows.

SearchUI.exe Barely Uses Any Resources, So Don’t Sweat It

“Cortana” (or SearchUI.exe) shouldn’t be using much in the way of resources if you examine it in the Task Manager. It’s not actually doing anything unless you open it.

With Cortana disabled with the registry hack, we noticed the Cortana (SearchUI.exe) process using 37.4MB of memory and 0% of our CPU.

You might wonder why Cortana is using any resources at all. That’s because it’s loaded in memory so it can instantly appear when you click the “Search Windows” box on the taskbar or press Windows+S.

When you open the search box on Windows 10, Cortana will use some CPU–but only as long as the search dialog is open.

Cortana shouldn’t appear to be using any more resources than this. It will always use a small amount of RAM in the background, and will use some CPU only when you open it.

The “Cortana” process doesn’t even handle file indexing. Windows indexes your files, examining them and the words inside them so you can quickly search them from the search tool. When Windows is indexing your files, you’ll see the processes like “Microsoft Windows Search Filter Host”, “Microsoft Windows Search Indexer”, and “Microsoft Windows Search Protocol Host” using CPU in the Task Manager.

To control indexing, open your Start menu or Control Panel and search for “Indexing Options”. Launch the Indexing Options shortcut that appears. This panel lets you choose the locations Windows indexes files in, choose the exact types of files, and exclude files you don’t want to index.

In summary, “Cortana” isn’t really running once you’ve disabled it. The basic Windows search interface, known as SearchUI.exe, remains running under the larger “Cortana” banner, even though the personal assistant really is turned off. SearchUI.exe uses a very small amount of RAM and only uses CPU when you have the search panel open, so it’s not something you should worry about.