Oh yusyus it works on Windows 8. I'm using it right now! x]
Windows 8 isn't blocking it; pretty certian it's Norton. Go to Norton's main console and lower its internet settings. If that doesn't work, go and look at your internet settings. If that doesn't fix it, check dat firewall. That could be ze problem.
It's defiantly not the hard drive. I think it's 623 GB. That's huge. XD Mine (Windows 8 Dell) has 905 GB on it's C: Drive. To see how much yew have left, go to Compter and right click C: > properties.
EDIT: I just saw how much GB takes on my PC with mods, presets, maps, etc. It takes 1.69 GB. That's nothing compaired to a PC.