Modern Windows® applications are very complicated "beasts". They include large numbers of files that are often saved in many different places, not just in the application's own program directory. In addition to this they also have even larger numbers of settings, sometimes hundreds, which they record in Windows' central database, which is known as the Windows® Registry.
Ashampoo UnInstaller Platinum Suite works by creating two "snapshots" of your system, one before you install an application and another one directly afterwards. These snapshots record the entire status of your computer system, including all registry entries, the locations, dates, sizes and versions of all files and the contents of all configuration files. After creating the second snapshot the program then compares it with the first and records all the differences in a special file called an "installation log file", or "log file" for short. When you tell Ashampoo UnInstaller Platinum Suite to uninstall the application it loads a previously created this log file and uses the information it contains to restore everything on your system to the way it was before you installed the application.
When you tell Ashampoo UnInstaller Platinum Suite to uninstall the application it loads this log file and uses the information it contains to restore everything on your system to the way it was before you installed the application.