A:Answer Hopefully you'll get a better answer, but it depends: What version is it? Do you have a subscription? Did you install it using a CD?
You can try checking here to see if you have a subscription: https://account.microsoft.com/services (you need to sign in) and you might see the download options there.
If you installed using a CD, you can just try that CD in your new computer to install it--you'll need to know your product key.
If you don't know the answers to these questions, you can also try to check for emails from Microsoft to see if your product key or re-installation instructions are there.
If you want further assistance, go here: https://support.microsoft.com/en-us/contactus/
