The logfile for sysprep is located in %systemroot%\System32\Sysprep\Panther and named Setuperr.log.
If an answer file is used during installation it will be saved and used when sysprep is run.
SYSPRP LaunchDll:Could not load DLL C:\Windows\SysWOW64\iesysprep.dll[gle=0x000000c1]
see technet post.
ImageX has be replaced by DISM, which is part of the ADK and can be downloaded from Microsoft's download center.
Dism /Capture-Image /Compress:maximum /ImageFile:c:\windows-partition.wim /CaptureDir:F:\ /Name:"Windows partition"
dism /mount-image /imagefile:c:\win7\sources\install.wim /index:1 /mountdir:c:\temp2 dism /unmount-wim /mountdir:c:\temp2 /commit dism /unmount-wim /mountdir:c:\temp2 /discard