[C++/NATIVE] inaccessible folder

[chants]

What if one recreates the first two folders, wouldn't the folder be accessible again?

What is the simplest and fastest and most practical (even using ACL and command line tools) to delete or bring about access to it again?

[gigaman]

The access is "prevented" just by the weird name (...) which many tools don't support. You don't have to use Native API - you can use the ordinary Win32 API, but you need to use the \\?\ prefix with the path.
You can even use the usual command line tools, e.g.

mkdir \\?\C:\\Winmend~Folder~Hidden\...\cn

or

rmdir \\?\C:\\Winmend~Folder~Hidden\...\cn

rmdir \\?\C:\\Winmend~Folder~Hidden\...