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(The following was tested with Windows Vista. Details may be different for other versions)
Telnet is both a protocol and a program (ref. 1).
One of the oldest Internet protocols, it dates back to 1969 (refs. 2,5), and in some ways is the
foundation of the modern Internet.
Both the HTTP (web browsing) and SMTP (email) protocols are based on it.
(1969 is also the year I used a computer for the first time, at a summer school, but that's another story).
I rely on Telnet, the program, for several tasks.
I use it to log-in on various servers and workstations.
I use it to test email and web servers (refs. 3,4).
I use it to get the weather forecast and climate data (more on that below).
The problem
To run the Telnet program, you can simply open a command prompt window, and type "telnet <remote-host-address>".
This has worked in almost every version of Windows upto and including XP.
When I recently upgraded to Windows Vista and tried the same thing, I discovered a problem (fig. 1 below).
Figure 1 - No Telnet.
Instead of being connected to the remote computer, the message
"'telnet' is not recognized as an internal or external command" appeared.
For some strangely shortsighted reason, Microsoft decided to omit the Telnet program from the
standard install of Vista!
Since I find it really useful, I decided to look into getting it back, and found two different ways of doing so.
These are described below.
The solution
The first solution, which I discovered while browsing the web, is to install the telnet program back.
Apparently the Vista install DVD contains the Telnet client, it is just not enabled by default.
To install the Telnet client, launch Control Panel, select "Classic View" and double-click on the
"Programs and Features" icon (fig. 2 below).
Figure 2 - Start "Programs and Features" control panel.
After a short pause, it shows the list of programs currently installed on your system.
Click on the link marked "Turn Windows features on or off" on the left side of the window (fig. 3 below).
Figure 3 - Click on "Turn Windows features on or off".
If Vista asks whether you want to allow this, click on "Continue".
A new dialog shows a list of features that you can add or remove.
Scroll down and locate the Telnet Client entry, and click on the box next to it to "check" it (fig. 4 below).
Figure 4 - Select the "Telnet Client".
Click on OK.
A dialog box shows the installer progress (fig. 5 below).
Figure 5 - Telnet Client install in progress.
After a few seconds, the install was complete, and a check with Windows Explorer showed the program telnet.exe was
now in the folder c:\windows\system32 (fig. 5b below).
Figure 5b - Telnet.exe now in c:\windows\system32.
When I opened a command prompt window and typed "Telnet",
it worked as expected (fig. 6 below).
Figure 6 - Telnet works from command line.
The second solution:
While Telnet was working now, I was curious whether I could also make it work by simply copying the Telnet executable
file from a Windows XP system.
It turns out the Telnet client is just a single file named telnet.exe in the folder c:\windows\system32
on a standard XP system.
First, I removed the Telnet client I had installed above by reversing the steps.
Next, I mapped the c: drive of an XP system as a network share (it became drive X: from the Vista system).
I dragged the file telnet.exe from x:\windows\system32 to c:\windows\system32 (i.e. from the XP machine to the
Vista machine) and got the following caution: (fig. 7 below)
Figure 7 - Copying Telnet from XP to Vista.
I was logged in as an Administrator, so I clicked "Continue".
This resulted in a somewhat unexpected error (fig. 8 below).
Figure 8 - Error while copying telnet.exe from XP to Vista.
For some unexplained reason, Vista was preventing me from copying a file into c:\windows\system32 from
a network share.
Perhaps this is another of the security features of Vista that I have not run across.
To solve the problem, I first dragged the telnet.exe from the X: drive to another folder on C: (C:\temp), then
moved it from c:\temp to c:\windows\system32 by just dragging it in Windows Explorer.
Vista did not complain this time, and I now had telnet.exe in the c:\windows\system32 folder (fig. 9 below).
Figure 9 - Telnet.exe is now in c:\windows\system32.
When I opened a command prompt window and typed "Telnet",
it again worked as expected (fig. 6 above).
All my testing so far has indicated that there is no functional difference between the two Telnet clients,
and because the XP version is about one-third the file size of the Vista version (compare figs. 5b and 9 above), I have decided to use
the XP Telnet on Vista for now, i.e. use the second solution.
Checking the Weather
One of the reasons I was keen to get Telnet working on Vista is that it makes it much simpler to get the
weather forecast.
This may seem strange when everyone from CNN to The Weather Channel offer weather forecasts via web browsers,
but it really is quicker with Telnet, and when you check the weather at least twice a day as I do, it adds up.
Weather data via Telnet is made available by the Weather Underground (refs. 6,7).
I have been using Telnet to access forecasts and climate data from this wonderful site since the early 1990's.
It is quick, accurate, and always up-to-date, and great credit must go its founder Jeff Masters for keeping it free.
To use it, you can simply type "telnet rainmaker.wunderground.com" at a command prompt, but that is too much
typing to be doing every day, so I created a desktop icon to do this chore, as follows:
The first step to was install Telnet on Vista, which I did as described above. If you are using Windows XP or 2000
then you already have Telnet.
Next, I created a new shortcut on my desktop.
I did this by right-clicking on a blank area of my desktop, and selected "New -> Shortcut" (see fig. 10 below).
Figure 10 - Creating a new shortcut on the desktop.
This brought up another dialog, and in the "location" field, I typed "telnet rainmaker.wunderground.com"
(without the quotes), then clicked on "Next" to continue. (see fig. 11 below).
Figure 11 - Creating Telnet shortcut.
I did not need to specify a location for telnet because it resides in c:\windows\telnet, which is in the
default search path for Windows.
This created a shortcut pointing to Telnet on my desktop.
I right-clicked on the shortcut icon, selected "rename", and renamed it to "Weather" (see fig. 12 below).
Figure 12 - Weather shortcut.
At this point I was done.
From now on, when I need to check the weather, I simply double click on the "Weather" shortcut, press the
"Enter" key once, and type the three letter code for the city whose forcast I need.
Because I entered the destination computer address as part of the shortcut, it automatically takes me to
the Weather Underground telnet server, and gets the weather data. The entire process takes about 5 seconds.
Fig. 13 and 14 below shows an example of getting the weather forecast for Madison, WI.
Figure 13 - Enter the city code...
Figure 14 - ..and get the forecast.
In case you don't know the city code, simple press the "Enter" key and the site guides you via a menu interface.
There is a lot of weather information there, including climate data and forecasts for hundreds of cities.
I encourage you to explore it if you have an interest in the weather.
Discussion
Two questions remain, why is the Telnet client not included in a standard Vista install, and why is the
Vista client so much bigger than the XP client.
[...To be continued...]
References
- Telnet (Wikipedia) http://en.wikipedia.org/wiki/TELNET
- Network Subsystem for Time Sharing Hosts - RFC 15 http://tools.ietf.org/html/rfc15
- Sending mail using Telnet http://www.yuki-onna.co.uk/email/smtp.html
- Telnet as a Diagnostic Aid http://usertools.plus.net/tutorials/id/21
- Telnet Overview and History http://www.tcpipguide.com/free/t_TelnetOverviewHistoryandStandards.htm
- The Weather Underground http://www.wunderground.com/
- The First Internet Weather Service http://www.wunderground.com/about/background.asp
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