net send command

These are a couple of examples:

To send a message to all users on your domain / workgroup you would do:

net send * Message 1

Likewise including your domain name / workgroup name would send to all users:

net send thisdomain Message 2

You can also send to individual computers:

net send computer1 Message 3

Finally, all attached users to a server (which ever machine you're sending from):

net send /users Get off my computer!

Here is Net Help Send.

The syntax of this command is:

NET SEND
{name | * | /DOMAIN[:name] | /USERS} message

Sends messages to other users, computers, or messaging names on the network. The Messenger service must be running to receive messages.

You can send a message only to a name that is active on the network. If the message is sent to a username, that user must be logged on
and running the Messenger service to receive the message.

name - Is the username, computername, or messaging name to send the message to. If the name is a computername that contains blank characters, enclose the alias in quotation marks (" ").

* - Sends the message to all the names in your group.

/DOMAIN[:name] - Sends the message to all the names in the workstation domain. If name is specified, the message is sent to all the names in the specified domain or workgroup.

/USERS - Sends the message to all users connected to the server.

message - Is text to be sent as a message.

all of which can be found by going to the COMMAND PROMPT... and typing: net send /?

Any dos based executable has a modifyer on the end that queries what it does ( /? )... So, in the future, if you do not understand what a file or prgram does that is dos / system executable, just put a /? after it for more info.

NET SEND {name | * | /DOMAIN[:name] | /USERS} message

Previous answer is correct for WinNT and later OS workstation.
For Win98 clients you must have open and running the "winpopup.exe" (you can find it in windows directory).
Add to startup a shortcut to this "exe" if you wish to start it automatically.

To example of net send using Windows.
click Start, point to Settings, point toControl Panel,click Administrative Tools, and then double-click Services.
Services mmc is appear.
Click Action,point All Tasks >> Send Console Message.click add(Computer name,Users names and Ipaddress).
Write message in "Message box". Then click "send" buttom. The message is send with Messenger service.