Install HP Scanjet Software after previous install was deleted

I am using an HP Scanjet G2410 scanner and previously installed the software on my external hard disk. The external hard disk stopped working and the software got deleted. I used Revo Uninstaller to uninstall the Registry Keys and remaining files. For three other softwares, I located the registry keys and deleted them. Now, when I try to install the software again, I find it telling that three softwares are installed (not what I deleted the registry keys for). I need all the software installed for the scanner to work properly. The software is not seen in Revo Uninstaller now.

Question by Sanoo on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.