You can simply update the following registry entries then restart windows explorer to remove copilot from windows.
Manually using the following:
Windows Registry Editor Version 5.00
[HKEY_CURRENT_USER\Software\Policies\Microsoft\Windows\WindowsCopilot]
"TurnOffWindowsCopilot"=dword:00000001
[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsCopilot]
"TurnOffWindowsCopilot"=dword:00000001
[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Edge]
"HubsSidebarEnabled"=dword:00000000
[HKEY_CURRENT_USER\Software\Policies\Microsoft\Windows\Explorer]
"DisableSearchBoxSuggestions"=dword:00000001
[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Explorer]
"DisableSearchBoxSuggestions"=dword:00000001
After updating your registry you can simply open task manager and right click on "Windows Explorer" then select restart. Now copilot will be gone.