Start command

Updated: 11/12/2023 by Computer Hope

The start command enables users to open a separate window from the Windows command line.

Tip

For help with how to start using the command line, see: How to use the Windows command line (DOS).

Availability

Start is an internal command that is available in the following Microsoft operating systems.

Windows Vista and later syntax

START ["title"] [/D path] [/I] [/MIN] [/MAX] [/SEPARATE | /SHARED]
         [/LOW | /NORMAL | /HIGH | /REALTIME | /ABOVENORMAL | /BELOWNORMAL]
         [/NODE <NUMA node>] [/AFFINITY <hex affinity mask>] [/WAIT] [/B]
         [command/program] [parameters]

"title"	Title to display in the window's title bar.
path	Starting directory.
/B	Start an application without creating a new window. The application has ^C handling ignored. Unless the application enables ^C processing, ^Break is the only way to interrupt the application.
/I	The new environment will be the original environment passed to the cmd.exe and not the current environment.
/MIN	Start window minimized.
/MAX	Start window maximized.
/SEPARATE	Start 16-bit Windows program in separate memory space.
/SHARED	Start 16-bit Windows program in shared memory space.
/LOW	Start application in the IDLE priority class.
/NORMAL	Start application in the NORMAL priority class.
/HIGH	Start application in the HIGH priority class.
/REALTIME	Start application in the REALTIME priority class.
/ABOVENORMAL	Start application in the ABOVENORMAL priority class.
/BELOWNORMAL	Start application in the BELOWNORMAL priority class.
/NODE	Specifies the preferred NUMA (Non-Uniform Memory Architecture) node as a decimal integer.
/AFFINITY	Specifies the processor affinity mask as a hexadecimal number. The process is restricted to running on these processors. The affinity mask is interpreted differently when /AFFINITY and /NODE are combined. Specify the affinity mask as if the NUMA node's processor mask is right shifted to begin at bit zero. The process is restricted to running on those processors in common between the specified affinity mask and the NUMA node. If no processors are in common, the process is restricted to running on the specified NUMA node.
/WAIT	Start the application and wait for it to terminate.
command/program	If it's an internal cmd command or a batch file, then the command processor is run with the /K switch to cmd.exe. The /K switch keeps the window open after the command is run. If it's not an internal cmd command or batch file, the command is a program that runs either as a windowed application or a console application.
parameters	These are the parameters passed to the command/program.

Note

The SEPARATE and SHARED options are not supported on 64-bit platforms.

Specifying /NODE allows processes to be created in a way that leverages memory locality on NUMA systems. For example, two processes that communicate with each other heavily through shared memory can be created to share the same preferred NUMA node to minimize memory latencies. They allocate memory from the same NUMA node when possible, and they are free to run on processors outside the specified node.

start /NODE 1 /AFFINITY 0x3 application1.exe
start /NODE 1 /AFFINITY 0xc application2.exe

If Command Extensions are enabled, external command invocation through the command line or the START command changes as follows:

non-executable files may be invoked through their file association by typing the name of the file as a command. (e.g., WORD.DOC would launch the application associated with the .DOC file extension). See the ASSOC and FTYPE commands for how to create these associations from within a command script.

When executing an application that is a 32-bit GUI application, CMD.EXE does not wait for the application to terminate before returning to the command prompt. This new behavior does NOT occur if executing in a command script.

When executing a command line whose first token is the string "CMD" without an extension or path qualifier, then "CMD" is replaced with the value of the COMSPEC variable. This change prevents picking up CMD.EXE from the current directory.

When executing a command line whose first token does NOT contain an extension, CMD.EXE uses the value of the PATHEXT environment variable to determine the extension. The default value for the PATHEXT variable is:

.COM;.EXE;.BAT;.CMD

Notice the syntax is the same as the PATH variable, with semicolons separating the different elements.

When searching for an executable, if there is no match on any extension, then looks to see if the name matches a directory name. If it does, the START command launches the Explorer on that path. If done from the command line, it is the equivalent to doing a CD /D to that path.

Windows XP and earlier syntax

START ["title"] [/Dpath] [/I] [/MIN] [/MAX] [/SEPARATE | /SHARED]
         [/LOW | /NORMAL | /HIGH | /REALTIME | /ABOVENORMAL | /BELOWNORMAL]
         [/WAIT] [/B] [command/program]
         [parameters]

"title"	Title to display in the window's title bar.
path	Starting directory.
/B	Start an application without creating a new window. The application has ^C handling ignored. Unless the application enables ^C processing, ^Break is the only way to interrupt the application.
/I	The new environment will be the original environment passed to the cmd.exe and not the current environment.
/MIN	Start window minimized.
/MAX	Start window maximized.
/SEPARATE	Start 16-bit Windows program in separate memory space.
/SHARED	Start 16-bit Windows program in shared memory space.
/LOW	Start application in the IDLE priority class.
/NORMAL	Start application in the NORMAL priority class.
/HIGH	Start application in the HIGH priority class.
/REALTIME	Start application in the REALTIME priority class.
/ABOVENORMAL	Start application in the ABOVENORMAL priority class.
/BELOWNORMAL	Start application in the BELOWNORMAL priority class.
/WAIT	Start the application and wait for it to terminate.
command/program	If it is an internal cmd command or a batch file, then the command processor is run with the /K switch to cmd.exe. Which means the window remains after the command is run. If it's not an internal cmd command or batch file, the command is a program that runs either as a windowed application or a console application.
parameters	These are the parameters passed to the command/program.

If Command Extensions are enabled, external command invocation through the command line or the START command changes as follows:

When executing a command line whose first token is the string "CMD " without an extension or path qualifier, then "CMD" is replaced with the value of the COMSPEC variable. This change prevents picking up CMD.EXE from the current directory.

.COM;.EXE;.BAT;.CMD

Notice the syntax is the same as the PATH variable, with semicolons separating the different elements.

Start examples

start notepad myfile.txt

Start a new instance of Notepad with the file myfile.txt.

start /MAX notepad

Start the notepad window with the screen maximized.

start /MIN mybatch.bat

The above example would start the batch file mybatch.bat in a minimized window.

start c:\music\"my song.mp3"

If the file or folder has a space in it, you must surround it with quotes. In the above example, we're starting the MP3 song file "my song.mp3." Without the quotes surrounding the file name with a space, you would get a Windows cannot find the file error.

start https://www.computerhope.com/

Open the Computer Hope web page in your default browser from the command line.