Microsoft Windows XP Professional Administrators Guide

System configuration data governs every aspect of an application's operation. Microsoft operating systems before Windows 95 stored system data in an assortment of files, such as:

• Win.ini

• System.ini

• config.sys

• autoexec.bat

In addition, applications sometimes store their own configuration settings in these files or in their own configuration files, leaving dozens of configuration files strewn all over the place and making administration extremely difficult. With the advent of the registry, most applications have moved the configuration data stored in all of these individual configuration files into the registry. The registry provides a single reliable storage location for configuration data. The registry contains many different types of configuration data, including:

• System settings

• Application settings

• Hardware settings

• User settings

• User account data

However, other system files still remain. Some files, such as win.ini and system.ini, are still around to support older applications that require these files in order to properly function. Other system files, such as Boot.ini, contain configuration settings that control specific Windows XP operations. The boot.ini file specifies settings that control the startup of Windows XP Professional.