Your Acer's built-in keyboard is compact to fit the laptop's design, adding portability to the laptop's features. If the built-in keyboard lacks the keys you need or you simply find desktop-style keyboards more comfortable, you can connect your wired keyboard to the Acer laptop, allowing more comfortable typing and increased functionality. Even the smallest of Acer's mini-laptops has at least one USB port, so this is the best interface for your wired-in keyboard. Keep in mind that an older keyboard may simply not be compatible with your Acer laptop.
Connect your keyboard's PS/2 connector (the round end of the cable) to a PS/2 to USB converter. Make sure the converter is designed for a keyboard, not a mouse, and that the packaging states that it is a signal converter, not just a simple adaptor. Modern computers require a different type of signal for the USB interface than a PS/2 provides, so without the proper adaptor your keyboard may not work.
Turn on your Acer laptop and plug the USB end of the converter into one of the USB ports. Follow any instructions to install a driver for the keyboard that appear on your screen. If no driver instructions appear or your computer is unable to find the appropriate driver on its own, visit the keyboard manufacturer's website and download the driver from there. Drivers are generally found in the "Downloads" or "Support" section of the website. If you cannot find the driver there, call the company to obtain the proper driver software.
Try typing on your external keyboard once the driver is installed. If it works, you are finished and should be able to use the keyboard any time without reinstalling the driver. If it doesn't work, you may need to manually tell your computer where to look for keyboard input.
Click "Start," then "Control panel," which may be under "Settings," depending on your version of Windows.
Click "Keyboard" in the Control Panel list. If you are using Windows 7 or Vista and do not see "Keyboard" listed, click on "Category" next to "View by" in the upper right corner of the window and switch to large or small icon view, then select "Keyboard."
Click the "Hardware" tab and select your new keyboard from the device list. If the window says the device is working properly, click "OK" to complete the keyboard set-up. If not, Windows will offer you a troubleshooting link. Click the link and follow the on-screen prompts to troubleshoot your device and repair it.