\shell\open\command is a deprecated way to associate a command with a protocol. That's why you are having problems, as WinSCP uses a recommended way to register, hence it wins (Note how WinSCP won't even overwrite your \shell\open\command).

The correct way to register is documented here:
https://learn.microsoft.com/en-us/windows/win32/shell/default-programs#registering-an-application-for-use-with-default-programs

Anyway, you can make WinSCP not register in installer:
https://winscp.net/eng/docs/ui_installer_selecttasks

Hi,
Prior to upgrade to Windows 10 (complete wipe), I had an HKEY_CLASSES_ROOT\SSH entry that pointed to a custom script that launches PuTTY with options from Chrome. Under Win7, after every WinSCP update, I had to restore that entry as WinSCP stepped on it.

Under Win10, same thing happens after WinSCP installation, but functionality is not restored after fixing the SSH registry entry. Attached screenshot shows current Chrome prompt. Prior to WinSCP installation, the outlined box read "Open sshexec.bat". That's my custom script from the \shell\open\command leaf of the registry entry - see full key below.

Please tell me how I can unlink SSH handling from WinSCP and restore the desired functionality. Thanks in advance.

----------------------------------------------------------------
Windows Registry Editor Version 5.00
[HKEY_CLASSES_ROOT\SSH]
@="URL:SSH Protocol"
"URL Protocol"=""
"EditFlags"=dword:00000002
"BrowserFlags"=dword:00000008
[HKEY_CLASSES_ROOT\SSH\DefaultIcon]
@="\"C:\\Program Files (x86)\\WinSCP\\WinSCP.exe\",0"
[HKEY_CLASSES_ROOT\SSH\shell]
[HKEY_CLASSES_ROOT\SSH\shell\open]
[HKEY_CLASSES_ROOT\SSH\shell\open\command]
@="sshexec.bat %1"