MS-DOS Version 7.0 (Windows 95)
DOS is provided with Windows 95 for backward compatibility with DOS and Windows 3.x applications. Let us see the evolution of MS – DOS to Windows in the following table:
MS – DOS Version |
Notes and Comments |
MS- DOS 1.0 |
First operating system on IBM PC in 1981 |
MS- DOS 1.25 |
Double sided disk support and bug fixes added |
MS- DOS 2.0
|
Introduced with IBM PC/XT in 1983 and having the support of hierarchical file structure and hard disks added. |
MS- DOS 2.01 |
2.0 with international support |
MS- DOS 2.11 |
2.01 with bug fixes |
MS- DOS 2.25 |
Support for Extended Character sets |
MS- DOS 3.0 |
Support for 1.2MB floppy disks and larger hard disks added |
MS- DOS 3.1 |
Support for Microsoft networks added |
MS- DOS 3.2 |
Support for 3.5 inches disks added |
MS- DOS 3.3 |
Generalized code page (font) support |
MS- DOS 4.0 |
Support for logical volumes larger then 32 MB and Visual shell |
Windows 1.0 |
Graphical user interface for MS – DOS |
Windows 2.0 |
Compatibility with OS/2, Presentation Manager |
Windows 95 |
Used Version 4.00.950 |
Windows 95 Se |
Used Version 4.00.1111 |
Windows 98 |
Used Version 4.10.1998 |
Windows 98 Second Edition |
Used Version 4.10.2222 |
Windows Millennium |
Used Version 4.90.3000 |
Windows NT |
Used Version 4.0 |
Windows 2000 |
Used Version 5.00.2195 |
Windows XP |
Used Version 5.1.2600 |
Necessary Commands
Let us learn some important commands that may be useful while we are trying to recover data by programming and non programming techniques:
ATTRIB
The ATTRIB command is used to display, set, or remove one or more of the four attributes, read-only, archive, system, and hidden that can be assigned to files and directories. It is typically used to remove read-only, hidden, and system attributes so a file can be moved or deleted or also to set them so that it can not be.
Syntax:
To display the attribute settings of all files in the current directory:
ATTRIB
To display the attributes of a directory:
ATTRIB directoryname
To display the attributes of a file:
ATTRIB filename
To set or remove attributes of a file or directory:
ATTRIB [ + | - R] [ + | - A] [ + | - S] [ + | - H] [directory|filename] [/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 allows a file to be accessed but not modified. The System attribute is normally reserved for files that are necessary for DOS or Windows to load properly. Files and directories with the Hidden attribute set are not normally displayed in directory listings or Open Files dialogue boxes.
The usual reason for hiding folders is because they are important to system or program operation and should not be deleted or moved in casual tidy-up operations. Hidden and System folders will often also have the Read-Only attribute set.
Multiple attributes can be set or cleared by combining switches, separated by spaces. Although both files and directories can have attributes assigned and cleared using ATTRIB, there are differences in the way they behave - the most obvious of which is that wildcards (? and *) can be used to display or change the attributes for a group of files whereas directories must be named in full. We are going to know in details about wildcards and shortcuts later in this chapter.
Setting a file attribute to System, Hidden, or Read-Only, will prevent the file from being deleted or moved using DEL, ERASE, or MOVE commands but will not protect the files from DELTREE or FORMAT. Although a directory's Read-Only attribute can be set, this seems to serve little purpose.
Firstly, the attribute only applies to the directory and not the files within it. Also setting a folder to read-only does not prevent it being deleted however in Windows explorer it will cause a warning notice to be displayed before the folder is deleted or moved.
To display the attributes of a file named "readme":
ATTRIB readme
To assign the Read-Only attribute to the file "readus.txt", use:
ATTRIB readus.txt +R
To remove the System and Hidden attributes from "data19.txt":
ATTRIB -S -H data19.txt
To hide the directory "c:\mynotes"
ATTRIB +H c:\mynotes
To hide the files, but not the directories in the C:
ATTRIB +H c:*.*
CD (or CHDIR)
Changes (or displays) the current directory on the specified drive.
Syntax:
To display the current directory:
CD [drive:]
To change the current directory:
CD path
Path Changes the current directory to path. Each drive has its own "current directory" which remains "current" until it is changed thus changing the current directory of drive c: will not affect the current directory status of any other drive. To change to the current directory on a different drive, just enter the drive letter and colon.
If the current drive is c:, to enter the directory "c:\windows\java"
CD \windows\java
If the current directory is already "c:\windows", all that is necessary is:
CD java
To change the current directory "c:\windows\java" to the parent directory "c:\windows":
CD..
Suppose you are currently in director “c:\windows\java\notes\klip\”, now if you directly want to jump to the windows directory, just increase the two more dots (..) you we did in the previous case, like this
CD….
If the current directory on the c: drive is "c:\windows\notes" and the current directory on the e: drive is "e:\movie", then to copy all files from "e:\movie" to "c\windows\notes":
COPY e:*.* c:
To copy all files from "e:\downloads" to the root directory of c:
COPY e:*.* c:\
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