I re-ran the installation on a different PC (also running Windows XP Professional Service Pack 3) . I restarted that PC straight after installing SenchaArchitect-2.0.0.exe but I still receive the error.
I have tested this on both our internal LAN and Wifi connections with no luck.
I will continue to investigate if this is an issue on my side. I use many applications that require Internet connection for registration and they do not have any issue finding my internet connections
On a side note the retry link on the error page does not give the user any feed back and I don't know if clicking on the link is actually doing anything.