Uninstalling an all-in-one printer

I have an hp officejet v40 that was not correctly installed though the prnter,fax,copier did install but not the scanner.Apparently since the installation did not run smoothly certain folders are missing in program files e.g the printer folder and certain basic files so it makes it difficult to troubleshoot.When trying out the uninstaller folder to uninstall the printer everything seems to be going fine but it’s just not uninstalling the printer.
When one reaches such a stage where you cannot uninstall to re-install what other options are there that allow one to uninstall ? Also becoz i cannot install the printer again without uninstalling.

Any help provided is greatly appreciated.
Thanks