If you are testing images by capturing them/cloning a system and then deploying then you probably will make more than one. However windows only allows a small number of sysprep runs (you have to sysprep the system before cloning to have an image as it was new). To make more than it is allowed, you need to reset the counter in the registry. Change these keys to these values:
HKEY_LOCAL_MACHINE\SYSTEM\Setup\Status\SysprepStatus\GeneralizationState\
CleanupState:2
HKEY_LOCAL_MACHINE\SYSTEM\Setup\Status\SysprepStatus\GeneralizationState\
GeneralizationState:7
Normally I just had to change GeneralizationState to 7 and didn't even have to restart. Run sysprep after changing and it should work!
More on that:
http://www.system-center.me/miscellaneous/sysprep-your-windows-os-for-more-then-3-times/