Activate AVG Ultimate on more than one device

Hi all!
My dad bought the AVG Ultimate because you could use it one more than one device but when I attempt to put the product on my own laptop, I keep having issues.
I've tried to sign in to his account to install it on my laptop and suddenly the email address and/or password is not recognised. I've also tried to activate the code using my own account, but it says activation code already used.
I'm not quite sure how to fix this issue? Help!

Hello, Christine.

I understand this must be upsetting. You must use the email address and password under which the product is registered to activate it. Please make sure that you are using correct email address and password (case sensitive) while entering them.

If the issue persist, I have sent you an email instruction to get connected with our technical support team. Follow those instructions to get in touch with them and you should be able to resolve your issue.

Hello, Christine.

I understand this must be upsetting. You must use the email address and password under which the product is registered to activate it. Please make sure that you are using correct email address and password (case sensitive) while entering them.

If the issue persist, I have sent you an email instruction to get connected with our technical support team. Follow those instructions to get in touch with them and you should be able to resolve your issue.