Hi,
If your devices are connected to PS/2 ports on the computer, verify that you have the following configurations:
· Verify that the USB plug for the keyboard is connected to the purple USB-to-PS/2 adapter and that this adapter is plugged in the keyboard PS/2 port on the computer. The keyboard PS/2 port on the computer may also be purple. If you are not sure which PS/2 port is the keyboard PS/2 port, see the documentation that was included with the computer.
Warning: If you have to change a PS/2 connection, shut off the computer, make the changes, and then restart the computer. Do not plug a PS/2 device into the PS/2 port while the computer is running.
If you have to change your configuration, shut down the computer, make the changes, and then restart the computer. If your mouse or keyboard has both USB and PS/2 connections, try using the other connection.
If the issue still persists, you may perform the steps provided.
**Method 1:**You may check if the PS/2 keyboard is getting detected on a different Windows 7 computer.
**Method 2:**You may run the Hardware troubleshooter and see if it helps.
Refer this link to do the same:
Open the Hardware and Devices troubleshooter
http://windows.microsoft.com/en-us/windows7/Open-the-Hardware-and-Devices-troubleshooter
Method 3:
You may need to reinstall the drivers for the devices.
Update a driver for hardware that isn't working properlyhttp://windows.microsoft.com/en-us/windows7/Update-a-driver-for-hardware-that-isnt-working-properly
Update drivers: recommended links
http://windows.microsoft.com/en-US/windows7/Update-drivers-recommended-links
Hope this information helps. Reply with the status so that we could help you further.