How to Uninstall non-drag-and-drop Program? I dragged a software (Abbyy Finereader 8 - old version) to external disc and noticed that it does not work there. 
I dragged it back and noticed it does not work there because of some internal problems, probably in registers. 

I removed the drag-and-drop Abbyy Finereader 8 and installed it again. 
The same problem persists. 

How can you clean the registers and other materials related to the installation? 
I want to install the app then afterwards again. 
The installation package does not have any app to fix the application.
When you install application software on any operating system it doesn't store anything permanently in processor (also known as CPU) registers. On Windows operating systems, application software does typically store information permanently in the Registry. OS X does not have a Registry, however applications may store similar information in PLIST files in the /Users/YOURUSERNAME/Library/Preferences folder.

Typically if you want to remove every trace of an application, you need to check the following folders as well as removing the application bundle itself.

 /Users/YOURUSERNAME/Library/Preferences
 /Users/YOURUSERNAME/Library/Application Support/APPLICATION OR COMPANY NAME
 /Users/YOURUSERNAME/Library/Caches/APPLICATION OR COMPANY NAME
 /Users/YOURUSERNAME/Documents/APPLICATION OR COMPANY NAME


Rarely software may also store files in the following extra folders. Be VERY CAREFUL making any changes within these folders. Make a bad decision and your Mac might not boot anymore.

 /Library/Application Support/APPLICATION OR COMPANY NAME
 /Library/Caches/APPLICATION OR COMPANY NAME
 /Library/Extensions
 /Library/LaunchAgents
 /Library/LaunchDaemons


As you can see it can be quite a lot of effort, which is why unless you are confident in what you are doing it is probably a good idea to use something like AppCleaner as recommended by Kevin in the previous answer.