I just bought a wireless key board and mouse set. The mouse won't work.

How to install wireless Keyboard and Mouse?Along with the development of the computer world, various brands of wireless keyboard and mice sets appear, you can purchase them from website or regular computer stores as well. Whatever your case may be, the directions for getting them ready for your computer are all basically the same. So, if you've bought a wireless set recently and you're having some trouble getting it to work, just follow these instructions and you'll be well on your way to wireless bliss!
First of all, wireless keyboards and mice aren't able to receive power from your computer like the wired ones do. Therefore, they need batteries to operate. And that's the first thing you need to do. Turn your keyboard over and you'll see a battery compartment. Take the cover off and insert the batteries according to the + - (plus, minus) compatibility. When you're done with the keyboard, you can go ahead and do the same thing for the mouse.
Once you've got the batteries in place, find a spot on your desk where you'd like to place both the keyboard and mouse. You won't have to move them around anymore, so make sure you find a place you'll be comfortable with. Now, while you're doing this, you'll also want to keep in mind where the wireless receiver will go. If you recall, a tip on that was in yesterday's newsletter.
The next thing you'll want to do is install the software that came along with your keyboard and mouse. Now, keep in mind that if you have Windows XP on your computer, you more than likely won't need to deal with the software at all. You can just plug the receiver into your computer and XP will automatically recognize the new hardware for you. On the other hand, if you're using an older version of Windows, you will need to install the software. To do so, just insert the disk into your CD ROM drive and follow along with the on-screen instructions. That's all you have to do!
The next step is connecting the wireless receiver to your computer, but again, if you have Windows XP, you've probably already done this. If not, it's likely that the wireless keyboard and mouse set you have works via a USB cable. So, all you have to do is find an open USB port on your computer and plug the receiver in. Once you plug it in, your computer will configure the keyboard and mouse so you can start to use them. You'll see a message that says something like "Your new hardware is now ready to use." (In XP, you'll get a pop up message that says "New Hardware Found"). Either way, that means you can now start using your new hardware!
Now that you've got everything set up, the next thing you'll want to do is test the keyboard and mouse, just to make sure everything's working properly. Go ahead and open some programs with your mouse and type some text in with your keyboard. Run through all the keys on your keyboard to make sure there are no problems with any of them and make sure all the buttons on your mouse work right.
Now, go on and enjoy your new wireless keyboard and mouse. Wireless really is the best way to go!

Maybe something crash with your OS. You can reinstall it maybe :D

I have the same problem and NO it is NOT the batteries! And you don't need drivers!
Anyone else have any ideas?

If it recognized it a couple of days ago, I'd recommend doing a system restore back to when it was working.

try replacing the key board battery or make sure that it is the correct way

My first guess is it could be the batteries. Have you tried changing it?

If it still won't work then I suggest reinstalling it.

Thanks for using Fixya!

Contact Microsoft

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They have the acer D255 laptop keys you need, take care.

Decide where the keyboard will be placed, whether it is on your desk or a table. Spend a little time experimenting with positions and placement to make sure your wrists and arms will be comfortable. You should consider ergonomics before you set up the keyboard to avoid repetitive motion injuries later on.

Step 2 Install the batteries (usually three AA) in your wireless keyboard. Replace the cover securely so the batteries are connected properly. Turn the keyboard on.

Step 3 Get out the wireless receiver that came with your keyboard. Position it close to your computer, but not closer than about 8 inches, as the computer itself can cause interference with the wireless signal. You will also want to set the receiver away from other interference-causing devices, such as radios, TVs and telephones.

Step 4 Ensure that your wireless receiver is no more than about 6 feet away from where you plan to set your keyboard.

Step 5 Insert the CD containing the accompanying software into your computer. A dialog box should appear on your screen. If the install instructions don't pop up right away, manually access the CD by double-clicking its icon or selecting it from the Start menu.

Step 6 Plug the wireless receiver into a free USB port on your computer. If you don't have any ports remaining on your computer, you can use an external USB hub instead.

Have you tried re-setting the frequency for one of the devices? simply click the button on the infra-red unit then click the button on the back of keyboard and notice the infra-red unit stopped scanning.