GW8.0.3 HP4 - GWIA install will not run!

I patched our server this weekend to 8.0.3 HP4 to address the security issues, and to be honest, I'm not sure which HP version of 8.0.3 I was on before that so figured it was a good thing to do regardless.
Anyway, the patch went as well as I'd expect it to, all seemed OK. After the Domain and PO's, I did the gateway installs. Ran the WebAccess install, all good. But the GWIA install will not run. On my Win7 WS it errors after accepting the license agreement. I then tried the install from my C: in compatibility mode, still crashes.

Anyone had any problems running the GIWA install at all? I suppose I could copy all the files manually, would that be suffice to patch the GWIA?

Cheers, Alan