1-3 OS Fundamentals part 3

1.2 Identify basic concepts and procedures for creating, viewing and managing files, directories and disks. This includes procedures for changing file attributes and the ramifications of those changes (for example, security issues). Content may include the following:

File attributes - Read Only, Hidden, System, and Archive attributes

ATTRIB [+R | -R] [+A | -A] [+S | -S] [+H | -H] filespec [/S]

• + Sets an attribute.
• - Clears an attribute.
• R Read-only file attribute.
• A Archive file attribute.
• S System file attribute.
• H Hidden file attribute.
• /S Processes files in all directories in the specified path.

The Read-only attribute

Before you can delete or overwrite a Read-only file, you must remove the Read-only file attribute bit.

The Hidden and System attribute

The purpose of the Hidden attribute is to make the file invisible in certain applications' file list display. These are usually important files the OS does not want you to play around with.

The System attribute, just as the name implies are usually files the OS needs to operate. In most Win systems, you will find about twenty files in the root directory which are marked both Hidden and System. These two attributes are often go hand in hand.

The Archive attribute

The purpose of the Archive attribute is to determine whether a file requires a back up (archiving). The Archive attribute is set whenever an existing file is either overwritten or modified. A new file is usually created with the Archive attribute set.

When you run the a back up program it will copy these archived files and then clear the Archive attribute, until the file is modified again.

File naming conventions (Most common extensions)

bat This is a batch file, commands may be put in here that run programs.

cab Cabinet file. Cab files contain multiple compressed files.

com These are MSDOS executables

drv Drivers

dll Dynamic Link Library

exe Executable files

inf Windows software or hardware information file.

ini Windows program initialization file.

mpd Miniport driver

sys System file

bmp Bitmap image file.

gif Image file.

jpeg Image file.

pif Program Information File. Used to start MSDOS applications in Windows 98.

vxd Virtual device driver

zip Compressed file

Windows 2000 COMPRESS, ENCRYPT

Compress

Windows 2000 uses compression similar to DriveSpace in windows 98, but unlike DriveSpace which compress entire volumes, it can compress individual files and folders.

You can compress files and folders only on drives formatted with NTFS, also compressed files and folders cannot be encrypted

If you add or copy a file into a compressed folder, it is compressed automatically. If you move a file from a different NTFS drive into a compressed folder, it is also compressed. However, if you move a file from the same NTFS drive into a compressed folder, the file retains its original state, either compressed or uncompressed.

To compress a file or folder

• In explorer select the file or folder you want to compress, choose properties
• Check the Compress contents to save disk space box

To remove compression from a file or folder, follow directions above and uncheck the Compress contents to save disk space box

Encrypt

Windows 2000 includes greater security than other versions of windows, with its Encrypting File System (EFS). It is based on public and private key encryption. The file system automatically generates an encryption certificate for the user along with a private key. You can encrypt individual files or folders, only on the NTFS file system.

When a user is logged on, they don't have to decrypt files to use them EFS automatically detects an encrypted file, locates the users private key and decrypts the file.

To encrypt a file or folder

• In explorer select the file or folder you want to encrypt, choose properties
• Choose advanced button to display the advanced attributes
• Check the Encrypt Contents To Secure Data box

To remove encryption from a file or folder, follow directions above and uncheck the Encrypt Contents To Secure Data box.

You can also encrypt file and folders from the DOS command prompt using cipher.exe If you do not use any command line options cipher will just display the encryption status of the folder.

cipher [/e | /d] [/s:dir] [/i] [/q] [dirname]

• /e Encrypts specified directory
• /d Decrypts specified directory
• /s : dir Specifies the directory to encrypt or decrypt
• /i Ignors errors
• /q Specifies a directory
• dirname

IDE/SCSI

IDE (Integrated Device Electronics) / EIDE (Enhanced Integrated Device Electronics) A type of disk drive interface in which the controller resides on the device itself.

SCSI(Small Computer System Interface) A standard high speed parallel interface, used for connecting peripherals such as hard drives, printers etc. You need an adapter card for SCSI devices.

Internal/External

Internal commands are built into COMMAND.COM. External commands are separate files and usually have an extension of .COM, .EXE, or .BAT.

Backup/Restore

Each time Windows 95 starts, it backs up the Registry by copying the current SYSTEM.DAT and USER.DAT files to SYSTEM.DA0 and USER.DA0

Windows 98 comes with Scanreg

If you have trouble starting windows 95/98 you can use a Start Up Disk, to create one, go to add/remove in control panel select Start Up Disk.

The Startup Disk is a bootable system disk with a collection of real-mode Windows 9x commands and utilities that you can use to restart your computer, 98 also adds a generic CD ROM driver, and other utilities.

Emergency Recovery Utility

The Microsoft Windows 95 Emergency Recovery Utility is designed to provide a backup of your system configuration in case a problem should occur.

Windows 2000 Emergency Repair Disk

The Emergency Repair Disk (ERD) can help you to repair or recover a system that can't load Windows 2000. The ERD helps you repair problems with system files and the partition boot sector. This situation occurs when your hard disk fails or when some of your system files are corrupted or accidentally deleted. System files are the files Windows 2000 uses to load, configure, and run the operating system. If some system files are missing or corrupted, you can use the ERD to repair those files.

Widows 2000 Recovery Console

Users can use the Recovery Console to repair Windows. This command-line utility can be used to copy system files, disable and enable services or drivers, repairing the Master Boot Record, etc. Only administrators have access to the Recovery.

Msbackup.exe

A built-in application that you run to back up the data or your entire system to prevent the loss of data in the event of hardware failure Name: Msbackup.exe Location: \program files\accessories \backup\msbackup.exe

Win 95 backup only supports QIC 40, 80, & 3010. tape drives

Win 98 msbackup supports the following:

• QIC-80 and 80 Wide, 3010 and 3010 Wide, and 3020 and 3020 Wide
• TR1, 2, 3, and 4 (Travan)
• DAT (DDS1 and 2)
• DC 6000
• 8mm
• DLT Removable media (floppy disks, Iomega Jaz or Syquest cartridges)
• Support has been added for parallel, IDE/ATAPI, and SCSI backup devices