You can only run sysprep twice. If you get an error the 3rd time follow these steps to fix it:
1. Change the following Registry key value of GeneralizationState to 7.
HKLM\System\Setup\Status\SysprepStatus
2. Run ‘msdtc -uninstall’ and ‘msdtc -install’ to repair the DTC installation.
3. Then re-run sysprep again and see if the issue is resolved.