how to disable Microsoft SmartScreen to allow download of critical app

Hi Ronald

I am Dave, an Independent Advisor, I will help you with this . . .

Open the Settings App (gear icon on your Start Menu)

Type 'app and' in the search box, and choose 'App and Browser Control' from the result

Click Reputation-based Protection Settings

Temporarily turn off all options on that page, then try installing that software

HI - I'm having a very similar issue, in that many/most of the programmes/apps that I opt to download I get the SmartScreen feature warning me they will harm my PC.

I have tried pretty much everything to prevent this happening - including following the advice to Turn off  'Reputation-based protection' along with all its options (Check app and files, SmartScreen for Microsoft Edge, Potentially unwanted app blocking and SmartScreen for Microsoft Store apps). All of them are off.  Protection history tells me 'Tamper protection is off, Check apps and files is off, and SmartScreen for Edge is off' - which should mean that SmartScreen shouldn't be doing anything! Yet it patently is.
As an example  I've been trying to download EaseUS' new PDF Editor program.

I've now tried dozens of times, always with SmartScreen advising me that "it could harm my PC". Yet, even though I opt to 'Keep' the program, even though I've said I trust it and gone ahead, when I am eventually allowed to save the file and try to Run or Install I'm told the program file is corrupt and I should get another copy!! The strange thing is that where Windows perhaps recognises the program I want (to download) as OK, the file is saved correctly. This corruption only happens when the Keep process is invoked.

I know and trust this EaseUS company and I have used their Disk programs for many years without issue. So I see no reason to believe that they would knowingly issue a program that's corrupted. And this happens with pretty much every program - be they .zip or .exe - when I do get them saved to disk, I'm always told that the saved file is corrupt. I therefore believe that when finally permitting the program to be saved, the Windows process is somehow corrupting the file, such that it won't run to install.

I've tried changing the setting to allow a new program through the firewall but that made no difference - and I'm just about at my wits end!

Since this is my own private PC (in that I am its Administrator!) there is no one else to reset any parameters in v.20H2 and Edge (canary) latest!