Purchased Internet protection for 3 PC's for 1 year

AVG Protection
2

Hi Jeff,

We'll certainly check on this.

Unfortunately, we are unable to locate the subscription details under your registered email address.

I have sent an email requesting additional information. Please check the email and reply to help you further.

3

Hi Jeff,

We'll certainly check on this.

Unfortunately, we are unable to locate the subscription details under your registered email address.

I have sent an email requesting additional information. Please check the email and reply to help you further.

1

I bought a 1 year subscription for 3 PCs. When I try and activate it , it says it's already used. 
I have installed it on one PC. Why won't it install on mine. I have Windows 10.