I wonder if you have any firewall software which might be stopping ArtRage from continuing further as it tries to check for updates. Here's a quick way to get around it though:
I've saved an artrage.prs ( settings file ) with updates turned off.
You can download it here:
From the start menu, run "Appdata" ( Windows key + R to open the run box ). This will take you to your application Data folder. Inside that, open Local, Ambient Design, ArtRage 2, and you should see your current artrage.prs file.
Make sure ArtRage is closed, then drop the prs file you just downloaded into that folder, overwriting the current one. You should now be able to launch ArtRage. Hope that helps!