If you are transferring all of your data and programs over to a new computer or you are planning on reinstalling your operating system, thus deleting all of your programs, you need to take the necessary steps before the transfer so that you can bring your software, such as Microsoft Office, over to your new computer. It involves only a few things, but make sure you take your time.
Turn on your computer and go into the Control Panel. Click "Uninstall a Program," "Programs and Features" or something similar depending on your operating system. Scroll down the list and select your Microsoft Office installation. It will ask you to verify the uninstallation. Click OK to uninstall. Uninstalling the software is needed so Microsoft knows that that you are not trying to install the same software on different computers.
Turn on your new computer, and insert the Microsoft Office installation disk into your computer's optical drive. Wait for a window to appear asking if you want to install the software. Click OK and click Recommended Install. This will do a complete install of Office onto your new computer.
Locate the product key on the back of your Microsoft Office packaging and keep it handy. Wait as the installation begins. It will ask you to input the product key. Type in the product key without any spaces or hyphens. Click OK.
Wait as the installation completes, and click "Finish" to confirm the installation is completed. Repeat this process whenever you are changing computers. If you fail to uninstall the copy of Office on your current computer before installing onto the new computer, the installation may fail. If it does, go back into your old computer and uninstall.