I just went through a reformat of my hard drive and a reinstall of XP--with the update to SP3. Now, Civ IV won't install at all. At first, the option to click Install would appear, but then it would hang. I've tried rebooting about ten billion times and nothing has worked. Now, all I get is the Sid Meier's Civilization 4 in the task bar, but nothing appears on the screen. What is the problem?