After successfully installing the Configuration Manager Client on a Windows Server 2003 I encountered an error when opening the Software Center:
After uninstalling and reinstalling the Configuration Manager Client the same error appeared.
Binging (yes, bing.com brought the solution!) the error, I found something similar here.
In this article is written, that .NET Framework 4.0 gets installed with SCCM2012 Client automatically. So I searched for it, and only found .NET Framework 3.5.
I downloaded the .NET Framework 4.0 , installed it and viola: Software Center got up without any errors 🙂