Have you built out the Task Sequence yet?
Did you create a capture boot media?
What error are you receiving?
I suggest following this guide. You can most likely skip the PXE part.
http://www.windows-noob.com/forums/index.php?/topic/6353-using-system-center-2012-configuration-manager-part-7-build-and-capture-windows-7-x64-sp1/