I've OpenSSH 7.6 installed in Windows 7 for testing purposes. SSH client & server work just fine till I tried to access one of my AWS EC2 box from this windows.

It seems like I need to change the permission on the private key file. This can be easily done on unix/linux with `chmod` command.

What about windows?

    C:\>ssh -V
    OpenSSH_7.6p1, LibreSSL 2.5.3
    
    C:\>ver
    
    Microsoft Windows [Version 6.1.7601]
    
    C:\>


    C:\>ssh [email protected] -i private-key.ppk
    @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
    @         WARNING: UNPROTECTED PRIVATE KEY FILE!          @
    @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
    Permissions for 'private-key.ppk' are too open.
    It is required that your private key files are NOT accessible by others.
    This private key will be ignored.
    Load key "private-key.ppk": bad permissions
    [email protected]: Permission denied (publickey).
    
    C:\>
    C:\>
    C:\>ssh [email protected] -i private-key.ppm
    Warning: Identity file private-key.ppm not accessible: No such file or directory.
    [email protected]: Permission denied (publickey).
    
    C:\>