Win32 Layered child windows

[howard.thomson]

My efforts to program a transparent but mouse event aware widget have yet to wrestle Windows 10 into submission, however I have just noticed this gem in the documentation footnotes:

'In order to use layered child windows, the application has to declare itself Windows 8-aware in the manifest.'

How would one 'declare' an Eiffel application to be Windows-8 aware ?

I have heard of the term manifest, but not having done any Windows programming since the 1990s, I lack familiarity of what it is all about ...

Currently, adding a flag WS_EX_LAYERED to the default extended style when creating a window causes a postcondition failure [the window is not created], and adding that flag using SetWindowLongPtr [per the documentation] is simply ignored (!) with an error return, but GetLastError() return of 0 (!!!!!).

Suggestions ?

[howard.thomson]

{WEL_WINDOWS_VERSION}.version_number_string returns "6.2.9200' which should be Windows-8 compatible ...

My program's behaviour, and Microsoft's documentation are incompatible !!!!