Windows Files and Folders
A virtual filing cabinet
Without a basic understanding of how computers and their files interact, you will not be able to understand the impact viruses and malicious code can have on a system.
A computer’s operating system and the programs that run on it are made up of individual files, most of which reside in directories or folders much like a filing cabinet. For example, most of the files associated with the Windows operating system might be found in a folder logically called Windows. Within the Windows folder are several subfolders (many of which also have subfolders) that help further categorize the files they contain. Files that don’t reside in a folder or subfolder are said to be on the root of the drive.
The actual name of the Windows folder can vary from system to system. For example, someone installing the Windows XP operating system might choose a folder name such as WinXP. Because of this, %windir% is often used in technical writing to imply the name of the Windows folder, regardless of what that actual name might be.
Think of your home filing cabinet. Perhaps you have a file folder named ‘Bills’ and inside that folder you have copies of individual bills you’ve paid. Perhaps you’ve even organized them using sub-dividers, so that the Bills folder is actually broken down into months or type of bills. Comparing that to a computer, the individual bills would be the files, the sub-dividers would be the subfolders, and the main folder ‘Bills’ would be a directory or folder found on the computer.
Terms to know:
Files
Folders
Subfolders
———————————————————————————-
The computer stores its files, folders, and subfolders on a hard-drive. Think of the hard drive as a single drawer in your home filing cabinet. There may be multiple hard drives on your system, just as there are multiple drawers in a filing cabinet. Hard drives are often referred to as fixed media implying that they cannot be easily removed from the computer. In conjunction with that is something called removable media, implying that it can be easily moved into or out of the computer. Like hard drives, the CD-ROM drive and the floppy disk drive are examples of fixed media, whereas the CD-ROM itself, or the floppy disk, are examples of removable media. Prior to the popularity of the Internet, removable media was the source of most virus infections. These viruses were said to spread by SneakerNet, implying that they were transmitted from person to person as they shared files and programs contained on floppy disks.
Fixed media such as hard drives, CD-ROM drives, and floppy disk drives are assigned drive letters by the operating system. Typically, the floppy drive is assigned drive letter ‘A’, the primary hard drive (also referred to as the local drive) is referred to as drive letter ‘C’, and subsequent hard drives or CD-ROM/DVD drives are referred to as drive letters ‘D’ through ‘Z’.
The Windows operating system is a graphical user interface (GUI) designed to allow manipulation of the files, folders, and subfolders and to allow easier manipulation of the hardware associated with the computer. Years ago, in the days before Windows, PCs used DOS. DOS was not a graphical interface and users were required to memorize the commands necessary to move through the folders to locate and execute (run) the desired program.
Consider the two screenshots below, both depicting the Windows\System subfolder as found in DOS and Windows Explorer, respectively. Which do you find easier?
Search
Antivirus Software
Sponsored Links
Stop Viruses Now
Visit Symantec for updated information and removal resources
enterprisesecurity.symantec.com
Email virus hoaxes
Breaking News, Insight and How To Defend Against Email Worms
security.eweek.com
F-Prot Antivirus Windows
Stop viruses dead in their tracks Protect your system now!
www.f-prot.com
Windows Files and Folders
Fixed and removable media
More on this feature
* Disks and drives
* Shortcuts and icons
* File types and extensions
Glossary
Help with this feature
The computer stores its files, folders, and subfolders on a hard-drive. Think of the hard drive as a single drawer in your home filing cabinet. There may be multiple hard drives on your system, just as there are multiple drawers in a filing cabinet. Hard drives are often referred to as fixed media implying that they cannot be easily removed from the computer. In conjunction with that is something called removable media, implying that it can be easily moved into or out of the computer. Like hard drives, the CD-ROM drive and the floppy disk drive are examples of fixed media, whereas the CD-ROM itself, or the floppy disk, are examples of removable media. Prior to the popularity of the Internet, removable media was the source of most virus infections. These viruses were said to spread by SneakerNet, implying that they were transmitted from person to person as they shared files and programs contained on floppy disks.
Fixed media such as hard drives, CD-ROM drives, and floppy disk drives are assigned drive letters by the operating system. Typically, the floppy drive is assigned drive letter ‘A’, the primary hard drive (also referred to as the local drive) is referred to as drive letter ‘C’, and subsequent hard drives or CD-ROM/DVD drives are referred to as drive letters ‘D’ through ‘Z’.
The Windows operating system is a graphical user interface (GUI) designed to allow manipulation of the files, folders, and subfolders and to allow easier manipulation of the hardware associated with the computer. Years ago, in the days before Windows, PCs used DOS. DOS was not a graphical interface and users were required to memorize the commands necessary to move through the folders to locate and execute (run) the desired program.
Consider the two screenshots below, both depicting the Windows\System subfolder as found in DOS and Windows Explorer, respectively. Which do you find easier?
Terms to know:
Fixed media
GUI
Local drive
Hard drive
Removable media
%windir%
———————————————————————————-
In Windows, the files, folders, and subfolders are represented by small pictures called icons. The icon for folders and subfolders intuitively looks like a folder. Icons for individual files assume the picture that either represents the type of file it is or represents the program it is associated with.
For example, the Windows operating system includes a program called “Notepad”. Notepad is a text editor, allowing documents to be created in plain text only without the special formatting options found in word processors. To the left we can see the icon for Notepad, which looks very much like a stenographer’s notebook.
Files created in Notepad or associated with it will maintain a similar look to the Notepad program icon. Take a look at the icon depicted on the left. This is an icon of a text file created in Notepad. Notice how it also looks like a stenographer’s notebook, this time with the cover flipped back – implying that it’s work that’s been done in Notepad.
As with real estate, location is everything. If a file used a particular program is moved or deleted, that program may no longer function correctly. This is because the location pointers are no longer valid. In Windows, location pointers are found in the System Registry. Think of the System Registry as a massive cheat list, laying out exactly where everything should be found and what it should be doing.
To make things easier, Windows allows users to create shortcuts. Many installation programs install shortcuts to their main executables. The Start | Programs menu is an excellent example of the use of shortcuts. Shortcuts are not the program or file itself, but rather a .lnk (link) file that provides a pointer to the original program or file.
For example, Notepad.exe is found in the Windows folder. Rather than browser there each time we wanted to use it, we can simply click Start | Programs | Accessories and launch it via the shortcut for Notepad that appears there.
Terms to know
Icons
Shortcuts
System Registry
———————————————————————————-
There are two main classes of file types on a computer: program files and data files. Program files are files that actually do something. Data files are the files created by those programs, usually by the user. For example, Microsoft Word is a word processing program with hundreds of files that allow it to work. When a user creates a document using Microsoft Word, it is a data file created in Word.
File types are defined by their extension. This three letter indicator at the end of a filename is solely responsible for letting the computer know what type of file it is, what program it is associated with, and how it should be handled. Using our Notepad example above, if we were to go to Start | Programs | Accessories | Notepad, we would be telling Windows to launch the Notepad shortcut (.lnk file), which in turn would open Notepad. However, if we were to go directly to the setuplog.txt file and open it, the .txt extension would tell Windows it was a Notepad file. In turn, Windows would open Notepad and display the setuplog.txt file within it.
All versions of the Windows operating system, by default, suppress file extension viewing. This is perhaps one of the worst decisions Microsoft has ever made, as it allows any number of viruses to use very basic tricks to entice users into opening files they should not or normally would not.
This problem comes into play because a filename accepts multiple periods. While a typical filename might be filename.txt there is nothing that prevents it from being file.name.txt. Thus, if a virus writer named a file filename.jpg.exe, only filename.jpg would appear to the user. This makes it appear as if the file were actually an image, when in fact it’s an executable. Windows has simply hidden the ‘real’ file extension from view.
The File Extension Center provides a step-by-step guide to configuring Windows so that file extensions are always displayed and provides a list of common executables that should be avoided in email.