At your own risk, you can try temporarily turning off/disabling your antivirus or firewall/security software first.
Then turn it back on after you have completed installing, patching, and/or successfully logged in and started playing the game.
For those of you having difficulty installing the game, here is a PDF guide PWE Tech Support has put together for you.
Available here: http://eso.perfectworld.com/media/ES...ationGuide.pdf
You might need Adobe Acrobat Reader or Sumatra PDF to open and read the guide.
Acrobat Reader is available here: http://get.adobe.com/reader/
Sumatra PDF is available here: http://blog.kowalczyk.info/software/sumatrapdf/
The Sumatra one has a smaller memory footprint, and is better for older systems.
The Adobe one obviously has more functionality.
Installation update: If you are having issues installing the game on Vista or Win7, try installing the game to the
\Games\Perfect World Entertainment\Ether Saga Online
directory so Windows won't give you such a hard time if you want Limited Accounts to be able to play it easily.