Batch File Windows 7 Activation

[Micol Cohn]

Allsupported versions of Windows and Windows Server have a set of Win32 console commands built in. This set of documentation describes the Windows Commands you can use to automate tasks by using scripts or scripting tools.

Windows has two command-line shells: the Command shell and PowerShell. Each shell is a software program that provides direct communication between you and the operating system or application, providing an environment to automate IT operations.

The Command shell was the first shell built into Windows to automate routine tasks, like user account management or nightly backups, with batch (.bat) files. With Windows Script Host, you could run more sophisticated scripts in the Command shell. For more information, see cscript or wscript. You can perform operations more efficiently by using scripts than you can by using the user interface. Scripts accept all commands that are available at the command line.

PowerShell was designed to extend the capabilities of the Command shell to run PowerShell commands called cmdlets. Cmdlets are similar to Windows Commands but provide a more extensible scripting language. You can run both Windows Commands and PowerShell cmdlets in PowerShell, but the Command shell can only run Windows Commands and not PowerShell cmdlets.

A reference of exit and error codes for Windows Commands can be found in the Debug system error codes articles that may be helpful to understanding errors produced. Windows Commands also include command redirection operators. To learn more of their use, see Using command redirection operators.

You can configure the Command shell to automatically complete file and directory names on a computer or user session when a specified control character is pressed. By default this control character is configured to be the tab key for both file and directory names, although they can be different. To change this control character, run regedit.exe and navigate to either of the following registry keys and entries, depending on whether you wish to change the value for the current user only, or for all users of the computer.

Set these values to that of the control character you wish to use. See virtual key codes for a complete list. To disable a particular completion character in the registry, use the value for space (0x20) as it isn't a valid control character. The type of value for this registry entry is REG_DWORD, and can also be specified by hexadecimal or decimal value.

You can also enable or disable file and directory name completion per instance of a Command shell by running cmd.exe with the parameter and switch /F:ON or /F:OFF. If name completion is enabled with the /F:ON parameter and switch, the two control characters used are Ctrl-D for directory name completion and Ctrl-F for file name completion. User-specified settings take precedence over computer settings, and command-line options take precedence over registry settings.

A batch file is a script file in DOS, OS/2 and Microsoft Windows. It consists of a series of commands to be executed by the command-line interpreter, stored in a plain text file. A batch file may contain any command the interpreter accepts interactively and use constructs that enable conditional branching and looping within the batch file, such as IF, FOR, and GOTO labels. The term "batch" is from batch processing, meaning "non-interactive execution", though a batch file might not process a batch of multiple data.

Similar to Job Control Language (JCL), DCL and other systems on mainframe and minicomputer systems, batch files were added to ease the work required for certain regular tasks by allowing the user to set up a script to automate them. When a batch file is run, the shell program (usually COMMAND.COM or cmd.exe) reads the file and executes its commands, normally line-by-line.[1] Unix-like operating systems, such as Linux, have a similar, but more flexible, type of file called a shell script.[2]

A .bat file name extension identifies a file containing commands that are executed by the command interpreter COMMAND.COM line by line, as if it were a list of commands entered manually, with some extra batch-file-specific commands for basic programming functionality, including a GOTO command for changing flow of line execution.

Microsoft Windows was introduced in 1985 as a graphical user interface-based (GUI) overlay on text-based operating systems and was designed to run on DOS. In order to start it, the WIN command was used, which could be added to the end of the AUTOEXEC.BAT file to allow automatic loading of Windows. In the earlier versions, one could run a .bat type file from Windows in the MS-DOS Prompt. Windows 3.1x and earlier, as well as Windows 9x invoked COMMAND.COM to run batch files.

The IBM OS/2 operating system supported DOS-style batch files. It also included a version of REXX, a more advanced batch-file scripting language. IBM and Microsoft started developing this system, but during the construction of it broke up after a dispute; as a result of this, IBM referred to their DOS-like console shell without mention of Microsoft, naming it just DOS, although this seemingly made no difference with regard to the way batch files worked from COMMAND.COM.

OS/2's batch file interpreter also supports an EXTPROC command. This passes the batch file to the program named on the EXTPROC file as a data file. The named program can be a script file; this is similar to the #! mechanism used by Unix-like operating systems.

Unlike Windows 98 and earlier, the Windows NT family of operating systems does not depend on MS-DOS. Windows NT introduced an enhanced 32-bit command interpreter (cmd.exe) that could execute scripts with either the .CMD or .BAT extension. Cmd.exe added additional commands, and implemented existing ones in a slightly different way, so that the same batch file (with different extension) might work differently with cmd.exe and COMMAND.COM. In most cases, operation is identical if the few unsupported commands are not used. Cmd.exe's extensions to COMMAND.COM can be disabled for compatibility.

COMMAND.COM and cmd.exe support special variables (%0, %1 through %9) in order to refer to the path and name of the batch job and the first nine calling parameters from within the batch job, see also SHIFT. Non-existent parameters are replaced by a zero-length string. They can be used similar to environment variables, but are not stored in the environment. Microsoft and IBM refer to these variables as replacement parameters or replaceable parameters, whereas Digital Research, Novell and Caldera established the term replacement variables[5] for them. JP Software calls them batch file parameters.[6]

This example batch file displays Hello World!, prompts and waits for the user to press a key, and then terminates. (Note: It does not matter if commands are lowercase or uppercase unless working with variables)

To execute the file, it must be saved with the filename extension suffix .bat (or .cmd for Windows NT-type operating systems) in plain text format, typically created by using a text editor such as Microsoft Notepad or a word processor working in plain text mode.

The interpreter executes each line in turn, starting with the first. The @ symbol at the start of any line prevents the prompt from displaying that command as it is executed. The command ECHO OFF turns off the prompt permanently, or until it is turned on again. The combined @ECHO OFF is often as here the first line of a batch file, preventing any commands from displaying, itself included. Then the next line is executed and the ECHO Hello World! command outputs Hello World!. The next line is executed and the PAUSE command displays Press any key to continue . . . and pauses the script's execution. After a key is pressed, the script terminates, as there are no more commands. In Windows, if the script is executed from an already running command prompt window, the window remains open at the prompt as in MS-DOS; otherwise, the window closes on termination.

Variable expansions are substituted textually into the command, and thus variables which contain nothing simply disappear from the syntax, and variables which contain spaces turn into multiple tokens. This can lead to syntax errors or bugs.

The usual way to prevent this problem is to surround variable expansions in quotes so that an empty variable expands into the valid expression IF ""=="bar" instead of the invalid IF ==bar. The text that is being compared to the variable must also be enclosed in quotes, because the quotes are not special delimiting syntax; these characters represent themselves.

The delayed !VARIABLE! expansion available in Windows 2000 and later may be used to avoid these syntactical errors. In this case, null or multi-word variables do not fail syntactically because the value is expanded after the IF command is parsed:

Another difference in Windows 2000 or higher is that an empty variable (undefined) is not substituted. As described in previous examples, previous batch interpreter behaviour would have resulted in an empty string. Example:

Unlike Unix/POSIX processes, which receive their command-line arguments already split up by the shell into an array of strings, a Windows process receives the entire command-line as a single string, via the GetCommandLine API function. As a result, each Windows application can implement its own parser to split the entire command line into arguments. Many applications and command-line tools have evolved their own syntax for doing that, and so there is no single convention for quoting or escaping metacharacters on Windows command lines.

However, escaping does not work as expected when inserting the escaped character into an environment variable. The variable ends up containing a live pipe command when merely echoed. It is necessary to escape both the caret itself and the escaped character for the character display as text in the variable:

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