You can download the installation files from the link below.

after installing the system you will need to free the licence.

you will need to use an account that has permission to access the registration module to login first.

If your old pc is still accessible you can use the un-register button to free up the licence.

Under 

Maintenance-> registration -> PC Id registration. 

If the old PC is not accessible, follow the link below to free the licence. 

After the licence is freed you can register the system