Based on my research, there were several known issues regarding "Windows Server Initial Configuration Tasks has stopped working" on pre-RTM Windows Server 2008 OS. And these issues should be fixed in RTM version.
Therefore, please first confirm whether you have installed Windows Server 2008 RTM version.
If so, please download and install .NET Framework 3.5 SP1:
Microsoft is conducting an online survey to understand your opinion of the Technet Web site. If you choose to participate, the online survey will be presented to you when you leave the Technet Web site.