Hi Mary Ellen, my name is ***** ***** welcome to JustAnswer!
When you say you have the registration number, are you referring to the product key? Does it look like sets of five letters separated by dashes?
Okay, thank you.
What we'll probably need to do is download the program from the Microsoft site and you then should be able to activate it with your product key. Are you experienced with installing software on the machine?
You no longer want assistance with installing Office?