I'm fairly sure it's a problem with Nprotect trying to load up. Nprotect is a company that created GameGuard, so if you disable game guard or remove it, that game might not boot up. There's more information located on the nProtect GameGuard Wikipedia Page.
Another forum posted it, well, I didn't get it very well, and he didn't answer yet and maybe never will. I looked into this site but it only says about Nprotect and GameGard, but not my problem, I looked GameGard FAQ and is not there either! I understood the load stuff, but how could that be? I just intalled DBO, opened the launcher (by the dbo.netmarble.net GAMESTART of course) and downloaded everything just as I downloaded everything of GameGard after the launcher, I haven't deleted it (in the beginning, after that I tried deleting it of course)...So. help me here please! Thanks =D
If you delete your gameguard map, It will redownload. I know Nprotect made gameguard, that's why I said to delete the GG map.
EDIT: I'm now on my laptop wich also has XP and also has the Nprotect failed problem.