When I set BingSearchEnabled = 0 in registry Windows search stops working. When I set BingSearchEnabled = 1 Windows search works again but includes web search which I do not want.
The setting is found in this registry key
Computer\HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Search These are all the settings found in the registry key
CanCortanaBeEnabled REG_DWORD 0x0 CortanaCapabilities REG_SZ PhoneCall,SpeechLanguage CortanaCapabilityFlags REG_DWORD 0x2200 CortanaConsent REG_DWORD 0x0 CortanaMUID REG_SZ MUID=9f732ec974834c269edf073bc3940476 DeviceHistoryEnabled REG_DWORD 0x0 HasAboveLockTips REG_DWORD 0x1 InstalledWin32AppsRevision REG_SZ {2BC03488-0C8C-4367-8AC4-73D37CC354B5} InstalledPackagedAppsRevision REG_SZ {A3EDD1F2-C5E4-4CC0-962C-090B859A87C0} ReplaceCortanaCheckRefreshed REG_DWORD 0x1 CortanaIsReplaceable REG_DWORD 0x0 CortanaIsReplaced REG_DWORD 0x0 CortanaInAmbientMode REG_DWORD 0x0 CortanaServiceTarget REG_SZ cortana.bing.com CortanaStateLastRun REG_BINARY 2E0E6A5D00000000 AnyAboveLockAppsActive REG_DWORD 0x0 IsWindowsHelloActive REG_DWORD 0x0 IsAssignedAccess REG_DWORD 0x0 NamespaceSettingsRevision REG_SZ {BFB53031-F975-40F4-90DA-1A76781F337D} BingSearchEnabled REG_DWORD 0x0 AllowCortana REG_DWORD 0x0 AllowSearchToUseLocation REG_DWORD 0x0 I'm running Windows 10 Home version 1903 (OS Build 18362.329) and I have the latest Windows updates according to Windows Update.
Here is a screenshot of what happens when I try to search: 
In the screenshot I first clicked the Start Button and then I typed "event viewer". In the upper left corner of the dark gray area, you'll find a small blue square. There are multiple of these, animated as if Windows was actually searching. I've obviously tried waiting to see if it would finish.
I've also tried asking Windows to rebuild the search index.
How do I make Windows search work without having web search enabled?
Update #1
Also worth noting that when BingSearchEnabled = 0 the process SearchUI.exe is constantly running at about 32% CPU.
2 Answers
When I set BingSearchEnabled = 0 in registry Windows search stops working. When I set BingSearchEnabled = 1 Windows search works again but includes web search which I do not want. It's also worth noting that when BingSearchEnabled = 0 the process SearchUI.exe is constantly running at about 32% CPU.
This is a known issue with KB4512941.
Windows Desktop Search may not return any results and may have high CPU usage Microsoft is getting reports that a small number of users may not receive results when using Windows Desktop Search and may see high CPU usage from SearchUI.exe when searching after installing KB4512941. This issue is only encountered on devices in which searching the web from Windows Desktop Search has been disabled.
Microsoft plans to patch this problem in September 2019.
We are working on a resolution and estimate a solution will be available in mid-September.
Source: Windows 10, version 1903 and Windows Server, version 1903
How do I make Windows search work without having web search enabled?
If you don't feel like waiting, for a fix to be released, I would revert back to KB4512508 (18362.295) by uninstalling KB4512941 (18362.329). In the end, the actions you have taken should have disabled the web searches and allowed local searches to work, without causing high CPU issues with SearchUI.exe.
The problem is linked to update KB4512941.
Microsoft say they will repair it mid-September.
