FTP doesn't run

Hi all,

My PC have Vista SP1, is connected in an intranet with ISA server 2003 with
a proxy, it has a fixed IP in my intranet. When I try to connect via FTP with
the internet, it waits until timeout and exits. I tryed to activate and to
disactivate the Windows Firewall, anyway the FTP doesn't run.
I searched for the log of the Windows Firewall with advanced protection on
the monitoring element (sorry, I have my os in Italian, I don't know if the
descriptions are right), but even with the firewall enabled or disabled, it
seems there is no access requests.
I tried also to force the change my IP address, but it seems it had no effect.

I tryed also to access via FTP to internet with another PC like mine (Vista
SP1, with my username), and it accessed. It seems one of the following:
- My PC have some wrong settings.
- ISA Server doesn't want that a PC with the name of my PC accesses to
internet via FTP.

I don't want change the name of my PC into the server domain beacuse of the
licence keys of programs installed into my PC.

I hope someone can help me.

Thank you.

Lucio