We have a pretty old logitech keyboard. It's a logitech 431879-0001. While typing on it, it starting acting strange. So we tried a USB keyboard and it worked just fine. We decided to change the batteries in the logitech and now it won't type at all. We have held down the connect button underneath and rebooted the computer to see if it would pick up the keyboard.

SOURCE: I need a owner manual for a logitech keyboard 431879-0001

You can go to;
http://lsearch.logitech.com/search?q=manual+keyboard&getfields=*&filter=p&hl=lang_en&btnG=Search&region=AMR&rq=0&sort=date%3AD%3AL%3Ad1&entsp=a&client=logi_us_en&lr=lang_en&entqr=3&accept-charset=iso-8859-1&oe=UTF-8&ie=UTF-8&style=us_en&proxystylesheet=logi_us_en&charset=utf-8&country=us&cl=US%2CEN&la=en&ud=1&language=en&getfields=*&output=xml_no_dtd&site=logi_us_en_products

Scroll down to your keyboard.
Click on "How to"

How to Use Your Keyboard and Mouse More Efficiently Whether you use your computer 8 hours a day or just a few times a month, you will benefit from the following user guide. It´s based on Logitech´s years of study into the most efficient ways to point, click, and type. And when you want to learn about how to improve the setup of your workspace, download our comfort guidelines.
Comfort Guidelines >>
A little bit of history: Computer keyboards are the successors of 19th century typewriters. The layout (location of the letters on the keyboard) has not changed since the invention of the typewriter. It is different for every country. The first computer in the 60's required a computer keyboard which had a design that was slightly different from what is available today on the market. However, the key layout is still the same and requires training to be used efficiently.
1. How to use your Desktop Your desktop comes with a keyboard and a mouse. Both devices work together to offer a typing, editing and navigating solution in a software environment. Follow these guidelines to use your keyboard and mouse:

• First place the keyboard in front of you on your desk. The right distance from your body is reached when your elbow is close to your side, and your fingers reach the center of the keyboard
• If you are right handed place the mouse on the right side of the keyboard.
• Have the mouse as close as possible to the keyboard allowing your hand to move the mouse without touching the keyboard with your thumb.
• When your hand moves from the mouse to the keyboard, the elbow should stay close to your side.
• If you have a palmrest, use it between keying tasks, not while typing. Using it while typing may increase pressure against the hand and increase the chance of injury.
• When mousing with your right hand, it is recommended to use the left-hand side of your keyboard with your left hand. There may be specific functions such as web navigation tools that you can do with your left hand. This is the 2 Handed Navigation feature that some Logitech keyboards have. It has an ergonomic benefit that is explained in the downloadable Desktop Design & Comfort. This may increase your productivity and reduce fatigue. Working, playing, communicating this way may make you more productive and may add a lot of comfort to your computing experience.

Desktop Design & Comfort >>
2. How to use your Keyboard A keyboard has more than 100 keys that can be typed. All these keys are located in 4 different areas which have different goals:

1. The alphanumeric keypad: the typing area T
2. he F row: the function keys
3. The numeric keypad
4. The navigation keypad

Keyboard Shortcuts >>
How to position your hands on a keyboard:

• Position your left hand on the left side of the typing area, have your left index finger positioned above the key F.
• Position your right hand on the center of the typing area, have your right index finger positioned above the key J. F and J keys have a raised little dot or a bar which allows you to easily feel the keys even if you don't look at the keypad.
• The navigation keypad and the numeric keypad are used only with the right hand. The F row is shared between both hands.

How to type:
There are 2 ways to type: either you touch-type with your 10 fingers without looking at the keypad while looking at the monitor or "hunt and peck" the keys with several fingers and your eyes look for the right keys. A keyboard is designed to be used with both usages.

• Every finger has a dedicated position on the typing area so that typing becomes a rapid and easy task. The following drawing shows these theoretical positions which is up to you to follow:
• Fingers must touch the center of the key and come back to a resting position (letters shown above the fingers) on the home row (the third row from the bottom, as indicated on the picture, where the keys F and J belongs to).
• When typing, the hand should float over the keyboard. When not typing, the hands can rest briefly either on the table or on the palmrest if it has been attached.
• Combination of keys: Shift, Control (Ctrl), and Alt Gr keys are used in combination with other alpha numeric keys on the typing area. They have to be pressed when another key is used.

3. How to use your Mouse A mouse is designed to be handled with one hand in order to move the pointer (also called the cursor - the little arrow) on the computer screen. A standard mouse has 2 buttons and a roller (also called a scroll wheel) between them.
How to position your hand on a mouse:
Place your hand on top of the mouse, and grip the mouse at your preference. If you are right handed, the index finger should click the left button.

You are now ready to mouse and click.
How to mouse and click:
Mousing should require only the motion of the fingers, not the whole hand. Look at the pointer on the screen and move the mouse between your thumb and pinky fingers according to your desired direction. Remember that the distance to reach an object on the screen is very small for the mouse and your hand on the table. For maximum precision, the 2 fingers should move less than a millimeter. You can configure the pointer speed by launching the Mouse Properties windows in the Control Panel, or with the manufacturer drivers.

The left button of the mouse is used to click on a software button on the screen (or an Internet link on a web page) to launch either a function, or a window etc. The right button is used to open a dynamic context menu close to the pointer position on the screen, from which commands can be launched, and then disappear. The roller between the 2 buttons on the mouse replaces the vertical scroll bar movement on the window to navigate up and down either on a page, a spreadsheet, a picture, etc: roll wheel up (extend your finger) to scroll up and roll wheel down (flex your finger) to scroll down. Usually all buttons are programmable to change their settings and functions depending on your preferences. Also, many mice now have additional buttons like an Internet Back in the thumb scoop of the mouse.

SOURCE: My keyboard is n't typing? I have a laptop.

reinstall the driver ..and check the plugs for proper insert ...if there was a problem and you started the pc ..and do not sow the device ...( problem like unpluging ..or out of batteries..) it is the chance that you need to go to the device manager ..and update the driver ...( from the disc ) or automatically cause the driver is still installed into the pc ...

SOURCE: My keyboard cannot type any letters. The keyboard

try checking with a different system like your friends.

SOURCE: My keyboard is typing double letters. I have

I had this problem after changing the batteries in Logitech Cordless Internet Pro Keyboard - Model Y-RAJ56A, very frustrating.
I am using a KVM switch that only has PS2 outputs and one of the computers doesn't have PS2 connectors for both keyboard and mouse. This necessitated another mouse & receiver. Receiver will accept both mouse & keyboard but initial installation didn't include pairing the KB with the receiver, it
picked it up from the KVM.
When I changed the batteries in the keyboard I instinctively pushed the buttons to pair the receiver to the keyboard.
Wrong move!
Now the computer is receiving keyboard command from both the former 'mouse only' receiver & the KVM, creating ddoouubbllee letters. After pairing, they refused to be unpaired.
Solution was to go to Control Panel, in Device Management and disable Wireless Keyboard. Now it only receives keystrokes from the KVM.
Problem was solved.

Hope this helps, Plasticman69