Hello CH-1. I understand you are attempt to resolve a scanning issue by reinstalling the software. I will provide some information that will be able to assist you in your quest.
Here is some information on uninstalling software: http://h10025.www1.hp.com/ewfrf/wc/document?cc=us&lc=en&docname=c02259020
Here is some information on installing software (including locating a driver: http://www8.hp.com/ca/en/support-topics/printer-installation/install-download-printer-drivers.html
Please respond when you complete troubleshooting so I know your results. I will continue to assist you if necessary.
Mario