The message 'Failed to load resource.DLL' pops up whenever I right-click on a document name or other similar items. After pressing OK the message disappears and I can continue my work as if this message was never shown. My system is Windows 10 fully updated.

1: My attempts to uninstall WS_FTP Pro 12.7 had apparently no effect! whatsoever.

2: Re-installing WS_FTP Pro 12.7 completed with no apparent problem.

3: my command to un-register wsftpsi.dll was rejected with error code 0x80070005 (I am logged on with administrator privileges!)

How can I proceed handling (and preferably fixing) this problem?