Can anybody please help?
On the Core Server there should be a log in the ManagementSuite\log directory.
Presumably you're not using provisioning. As Rhyous suggested, you'll need to post the log for the imaging job. It sounds like there is a problem with the deployment of the image, and since the sysprep is injected to the drive after the image runs, the task terminates before inserting the sysprep.inf to the hard disk. The log should be named something like CJ-<your imaging job name><time and date>.log