Trying to delete current version of software but can't

Question

I am attempting to load an older version of my scansnap software ( it's more functional) but it tells me I cannot because a newer version exists ... I have deleted the program , gone through all the library's etc to find any preference files or any files at all referencing 'scansnap' and deleted all of them and emptied the trash, all to no avail. Fujitsu doesn't discuss this at all on their support site nor does it include any kind of uninstall software.. Any help would be greatly appreciated!
Thanks in advance!

Answer 1

Uninstalling Software: The Basics
Most OS X applications are completely self-contained "packages" that can be uninstalled by simply dragging the application to the Trash. Applications may create preference files that are stored in the /Home/Library/Preferences/ folder. Although they do nothing once you delete the associated application, they do take up some disk space. If you want you can look for them in the above location and delete them, too.
Some applications may install an uninstaller program that can be used to remove the application. In some cases the uninstaller may be part of the application's installer, and is invoked by clicking on a Customize button that will appear during the install process.
Some applications may install components in the /Home/Library/Applications Support/ folder. You can also check there to see if the application has created a folder. You can also delete the folder that's in the Applications Support folder. Again, they don't do anything but take up disk space once the application is trashed.
Some applications may install a startupitem or a Log In item. Startupitems are usually installed in the /Library/StartupItems/ folder and less often in the /Home/Library/StartupItems/ folder. Log In Items are set in the Accounts preferences. Open System Preferences, click on the Accounts icon, then click on the LogIn Items tab. Locate the item in the list for the application you want to remove and click on the "-" button to delete it from the list.
Some software use startup daemons or agents that are a new feature of the OS. Look for them in /Library/LaunchAgents/ and /Library/LaunchDaemons/ or in /Home/Library/LaunchAgents/.
If an application installs any other files the best way to track them down is to do a Finder search using the application name or the developer name as the search term. Unfortunately Spotlight will not look in certain folders by default. You can modify Spotlight's behavior or use a third-party search utility, Easy Find, instead. Download Easy Find at VersionTracker or MacUpdate.
Some applications install a receipt in the /Library/Receipts/ folder. Usually with the same name as the program or the developer. The item generally has a ".pkg" extension. Be sure you also delete this item as some programs use it to determine if it's already installed.
There are also several shareware utilities that can uninstall applications:
AppZapper
CleanApp
Yank
SuperPop
Uninstaller
Spring Cleaning
Look for them at VersionTracker or MacUpdate.
For more information visit The XLab FAQs and read the FAQ on removing software.