Windows Troubleshooter Guide/C:\WINDOWS

The C:\WINDOWS directory (in some versions of Microsoft Windows, such as Windows 10, it appears as C:\Windows), is commonly remembered as the folder containing the Windows operating system. Although every file in the C drive is technically used by the OS, the C:\WINDOWS folder contains the files that, in turn, contain the code to run the OS.

Since folders can be renamed, this directory is commonly referenced through the environment variable, which itself can be modified when the directory changes to make the desired effect.

Overview
The C:\WINDOWS folder is the initial directory for the OS. However, you will not find the entirety of the files composing the OS here. You will find a good deal more in the System folders. Depending on your version of Windows and the types of programs you installed (be they purposefully installed or installed maliciously), the contents may differ. Good troubleshooting begins with knowing what should be in a directory and what is fine if left alone.

Files
In a typical installation of Windows, you may find that the C:\WINDOWS directory already contains some files. Some of these files (especially the text files ending in .log) are essentially not necessary in keeping the OS working, but others are. The list is below.

Folders
The more meaty aspect of the Windows operating system is found in subdirectories of the C:\WINDOWS directory. Folders which have significant aspects to understanding the OS have their own links. The rest are found here.