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 %windir%, which itself can be modified when the directory changes to make the desired effect.

Note

Exercise some level of reasoning when analyzing what files do. Many files do not have associating descriptions and can only be inferred. Others may be illegible acronyms. As always, exercise caution when traversing the C:\WINDOWS directory

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.

Description of Typical Executables in C:\WINDOWS (Windows 10)
Filename	Description (Provided)	Description (Reasonable Guess)
`bfsvc.exe`	Boot File Servicing Utility	Runs the files necessary for booting the OS. May involve the BIOS.
`explorer.exe`	Windows Explorer	Runs the GUI of the OS and the file browser you are using to view the C:\WINDOWS directory. Of critical importance.
`HelpPane.exe`	Microsoft Help and Support	???
`hh.exe`	Microsoft® HTML Help Executable	Runs the help dialog popup found in some programs.
`notepad.exe`	Notepad	The Notepad application.
`regedit.exe`	Registry Editor	The Registry Editor application.
`splwow64.exe`	Print driver host for applications	The application used to handle printing jobs. Note that the wow64 distinction hints that this is a 64-bit application and that 32-bit OS's may be different.
`winhlp32.exe`	Windows Winhlp32 Stub	Runs the help dialog popup found in some programs, here for legacy programs.
`write.exe`	Windows Write	Runs a Windows writing program bundled with the OS (usually WordPad), here for legacy programs.

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.

Description of Typical Folders in the C:\WINDOWS Directory (Windows 10)
Directory	Description of Contents (Reasonable Guess)
`assembly`	Contains .NET assembly programs that are meant to be shared among Windows programs ^[1]
Boot
Cursors	Contains a list of icons used for the mouse cursor. Each file is in the `cur` format.
debug
diagnostics
DigitalLocker
en-US
Fonts	Contains the list of available fonts for the OS. The Control Panel's Font icon direct to this folder. As a directory, it stores each font file in a machine-friendly manner.
Globalization
Help
IME
ImmersiveControlPanel
INF
InputMethod
Logs
Media
MiracastView
OCR
Offline Web Pages
Panther
Performance
PLA
PolicyDefinitions
PrintDialog
Provisioning
PurchaseDialog
Registration
rescache
Resources
security
ServiceProfiles
servicing
Setup
SoftwareDistribution
Speech
`System32`	On a 64-bit edition, this directory contains a 64-bit instance of necessary OS files made for 64-bit program. On a 32-bit edition, this directory contains a 32-bit instance of necessary OS files made for 32-bit programs. ^[2]
SystemApps
SystemResources
`SysWOW64`	A 32-bit instance of necessary OS files made for 32-bit programs on a 64-bit Windows operating system edition. Does not exist on a 32-bit edition. ^[3]
Temp
Web
WinSxS

References

↑ "Global Assembly Cache". Microsoft Developer Network. Microsoft. Retrieved 30/12/2015. {{cite web}}: Check date values in: |accessdate= (help)
↑ "SystemFolder property". Microsoft Developer Network. Microsoft. Retrieved 30/12/2015. {{cite web}}: Check date values in: |accessdate= (help)
↑ "File System Redirector". Microsoft Dev Center. Microsoft. Retrieved 30/12/2015. {{cite web}}: Check date values in: |accessdate= (help)

[1] "Global Assembly Cache". Microsoft Developer Network. Microsoft. Retrieved 30/12/2015. {{cite web}}: Check date values in: |accessdate= (help)

[2] "SystemFolder property". Microsoft Developer Network. Microsoft. Retrieved 30/12/2015. {{cite web}}: Check date values in: |accessdate= (help)

[3] "File System Redirector". Microsoft Dev Center. Microsoft. Retrieved 30/12/2015. {{cite web}}: Check date values in: |accessdate= (help)

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