Thank you for your message. Please if possible, translate the error message that you are getting so that we will be able to assist you better,
Also, if you are able to boot back to into the OS by switch from AHCI to raid on, please do so. You will be able to create an image of the OS from within the OS by running the Dell OS recovery tools there.
There would be two options, one to create an online image and one to create an offline image. You can choose to create the offline image but it would consume more space on the flash drive.