birdman64 – 44 minutes ago  » 

H What is the largest hdd that can be fitted to the 9300t? How do i install the software on the new hdd?

I think units bigger than 1TB have refused to format. You need to consider whether it is worth going bigger than about 500MB as (regardless of disk size) there is a maximum limit of 512 recordings. There is no software stored on the disk so it should just be a matter of installing the new drive turning on the 9300 and answering Yes to the prompt to format the drive.