Adding a second laptop to my account

Hello Rose. 
We're glad to help you with this.
To add another device to your AVG subscription, you need to manually install & activate the AVG subscription/program on that device.
Please refer to the below articles to install & activate your AVG Internet Security (Multi-Device) subscription on your other device:
Installing AVG Internet Security (https://support.avg.com/SupportArticleView?urlname=Install-AVG-Internet-Security)
Activating AVG Internet Security (https://support.avg.com/SupportArticleView?urlname=Activate-AVG-Internet-Security)
Activating product will also install the remaining products on your account on the device.
Let us know if you need further assistance.

Anyone know how to add another laptop to an existing account please?

Hello Rose. 
We're glad to help you with this.
To add another device to your AVG subscription, you need to manually install & activate the AVG subscription/program on that device.
Please refer to the below articles to install & activate your AVG Internet Security (Multi-Device) subscription on your other device:
Installing AVG Internet Security (https://support.avg.com/SupportArticleView?urlname=Install-AVG-Internet-Security)
Activating AVG Internet Security (https://support.avg.com/SupportArticleView?urlname=Activate-AVG-Internet-Security)
Activating product will also install the remaining products on your account on the device.
Let us know if you need further assistance.