How do I delete the file - sfShellTools.dll

I've uninstalled SmartFTP but what remains is this file, sfShellTools.dll, in the Program Files / SmartFTP directory. I can not delete it. Which process do I need to delete/remove before I can delete this file.

Any help appreciated.

When uninstalling with the setup all files will be removed properly. To manually delete the file:
regsvr32.exe /u sfShellTools.dll
Then reboot and delete the file

When uninstalling with the setup all files will be removed properly. To manually delete the file:
regsvr32.exe /u sfShellTools.dll
Then reboot and delete the file

Thank you......