Dell does not ship re-installation media along with the system as the comes equipped with a restore partition which users can use to reset the system back to factory settings. Also, the system comes with Dell Backup and Recovery Manager software that you can use to create recovery media for use in such situations.
Since you have not created the recovery media and also the hard drive has been partitioned, the factory image is not there any longer. Please share the system's Service Tag and Owner's Name with me via private message (click my username and then click Start Conversation). I'll review the details and check what best can be done for you.
Please reply with the information.