If you have purchased a Legacy or Starter Pack, please see this thread for instructions on how to claim your items in-game. (Please see the yellow text in the linked thread for instructions on creating a Reman.) (Not seeing your pack in-game? Please see the lime-green text in the linked thread above for information.)
If you have additional questions about the Legacy or Starter pack, please read this FAQ.
Thanks SO MUCH for all your support, and we'll see you in-game!
I bought the download version through gamestop and found that it had finished downloading in the morning. When I attempt to install, the installer fails when extracting files at the very beginning. The last one to extract is infinist.exe.
Then I get the error message that the main setup application could not be launched.
Since you bought a digital download, has Gamestop given you your serial number yet? If they have, then I believe you can register your account here (which you'll have to do anyway) and then simply download the file directly from Cryptic. Unless I completely fail to understand the system involved, you don't have to use the version from a digital retailer (and given some of the issues I've heard with patching and updates, it's quite possible that you don't really *want* to use a retailer's version.)
If you still can't get the Gamestop file to download and decrypt properly, you might give that a try.
Edit: Also, you said you're running XP SP2 - you might need to consider installing SP3, and the updates to Internet Explorer. As I understand it, the launcher is essentially a script that runs through IE, and things get weird if you're not using the current version.