pol 1160 errorFollow

I had ffxi installed on my computer and it was running just fine. I was leaving to go on vacation so i uninstalled everything and have tried installing it on my uncles computer... All disks installed fine but now when i try going online through the playonline i get the error 1160. His internet is working fine and have checked and server is not down. I have disabled anti virus programs during install etc but still get this error how can I fix it???
Thanks