Hi,
Welcome to Microsoft Community and thank you for posting the question. As per the description, you are unable to complete the installation of Microsoft Wireless Keyboard 800 desktop 2.4ghz transceiver v 8.0.
I understand it must be very difficult when things do not work as expected. Please answer few questions to narrow down the issue.
- Are you trying to install the application software by CD/DVD or through Online?
- What is the complete error message?
- Are you able to install other program successfully?
I would suggest you to download the driver for the device from the article below and check with the issue.
Wireless Keyboard 800
http://www.microsoft.com/hardware/en-us/p/wireless-keyboard-800/2VJ-00001#support
Provide more information regarding the issue so that we could help you further.