Cortana in Windows 10 uses a lot of resources. You can safely remove or disable Cortana in windows 10.
There are two methods you can use to disable Cortana. Use method 1 if you have windows 10 Professional or above version. If you have windows home or premium version please use method 2.
I strongly recommend you to create the system restore before using any of the below methods. So if you run into any issue you can always go back to the previous stage of the windows.
Method 1:
Type Group Policy in Windows 10 Search
Open Group Policy editor
Navigate to Local group Policy --> Administrative template --> Windows components --> Search (Please check Image above)
Here right-hand side you will see Allow Cortana.
Double click and open it. Here click on Disable and press Apply and OK
Navigate to Local group Policy --> Administrative template --> Windows components --> Search (Please check Image above)
Here right-hand side you will see Allow Cortana.
Double click and open it. Here click on Disable and press Apply and OK
Reboot your computer. Now you will still see Cortana in windows 10 process but it will run only for windows search.
Method 2:
If you have windows 10 home or premium version you need to use the registry editor to disable Cortana.
Open registry editor by typing Regedit in windows search
Navigate to Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Windows Search
Righ hand side you will see AllowCortana . Double click on it and change Hexadecimal value to 0
Reboot your PC. If you don't see AllowCotrana right click on blank space and create Dword. Make sure you name exactly AllowCortana (A and C capital)
Hope this has helped you. Please leave your comments. Thanks a lot