I'm sorry about the issue. To confirm, is it the product key of your Microsoft Office?
What's the version of your Microsoft Office, such as Office 2003, 2007, 2010, 2013, 2016, 365, etc.?
Where did you purchase Microsoft Office previously?
Do you have windows xp, vista, or 7, or 8, 10, or mac computer?
Please reply at the box below. Thank you.
When did you purchase it?
Do you remember the website link where you purchased it from?
Did you receive any order confirmation email for Microsoft Office?
Since your son purchased Microsoft Office, then he probably used his email address; if so, then MS Office order confirmation email message would be in his email account.
Can you check with your son?
Please let me know. Thank you.
When you get the Microsoft Office purchase information from your son, then please let me know, so we can continue.
Or I can install an alternate Office program, that is free, you can use and see if you like it or not. It's similar to Microsoft Office program.
Please reply at the box below any time to continue. Thank you.