1. EXTERNAL COMMANDS
1) ATTRIB(Attribute) :- This command allows the user to
change the properties/attributes of a specific file. Using attrib command , the user has capability of changing the file to have any of the below attributes e.g. read only . Hidden , archived.
(a) C:\>ATTRIB (press enter)
(b) This will display all files in the current directory and each of their attributes. If any file is hidden it will display that file.

2. 2) CHKDSK (Check Disk):- it checks the computer’s hard disk drives status for any cross-linked or any additional errors with the hard disk drive , but it cant repair the problems found. It returns the volume serial number , total disk space , space occupied by hidden files. Syntax :- C:\> chkdsk [drive name] Example :- C:\>chkdsk D: (press enter) It will check the status of D: drive

3. 3) SCANDSK:- It is used to check and repair various kinds of disk errors. It thoroughly checks the disk and reports any kind of bad sectors. This is an extension of chkdsk command. Syntax :- C:\>Scandsk [drive name] (press enter) Example :- C:\> scandsk D: (press enter) 4) BACKUP:- It enables users to backup their data on their computer . C:\> BACKUP [SOURCE PATH] [TARGET PATH]

4. 5) RESTORE:- It is used to restore files copied by BACKUP command
5) RESTORE:- It is used to restore files copied by BACKUP command. Syntax :- C:\> RESTORE [SOURCE PATH] [TARGET PATH] 6) FORMAT:- The newly created disk partitions are generally unformatted and cannot be directly used to store data. These disks have to be formatted with FORMAT command. C:\>FORMAT [drive name]/SWITCHES

5. 7) FIND:- It allows you to search for text within a file
7) FIND:- It allows you to search for text within a file. Syntax :- C:\> FIND “REM” AUTOEXEC>BAT (press enter) It will search a string “rem ” from the file AUTOEXEC.BAT 8) SYS(System):- It is used to copy the system files from one drive to another drive C:\>SYS A: (press enter) It will copy all the system files from C:drive to A: drive

6. 9) TREE:- it will display the list of files and sub directories of a given directory in a tree like structure . Syntax :- C:\>TREE [PATH] Example:- C:\> TREE/F It will display all the directories as well as sub- directories of the root directory of C drive in a tree like structure.

7. 10) MOVE :- It allows you to move files from one directory to another or from one drive to another. Syntax :- C:\> MOVE D:\*.* E:\ (press enter) It will move all the existing files from the root directory of D: drive into root directory of E: drive 11) DELTREE :- It deletes all the files and sub directories of a given directory completely. It prompts to verify deletion which can be removed by using the switch ‘y’. DELTREE[/Y][DRIVE:][PATH] C:\>DELTREE D:\Bca*.* It will delete all the files in “BCA” directory of D:drive

8. 12) LABEL:-It is used to view or change the label of the computer disk drives. Syntax :- C:\>LABEL[drive:][label] Example :- C:\>LABEL D: PKS It will change the label of D:drive to “PKS”.

9. 13) DISKCOPY:- It allows the user to copy the complete contents of a disk into another disk . It first formats the target disk and then copies the files by collecting files from the source disk and copies to the target disk. Syntax :- C:\> DISKCOPY [source path][target path] Example :- C:\> DISKCOPY A: B: It will copy the entire contents from the source disk A: into target disk B:

10. 14) UNDELETE:- It allows the user to restore files that may have been deleted. Syntax:- C:\>UNDELETE [Drive:][PATH][FILE] 15)XCOPY:- It is a powerful version of COPY command with additional features. XCOPY has the capability of moving files, directories , and even whole drives from one location to another. C:\> XCOPY [SOURCE PATH] [TARGET PATH]