Hi, I sent you the link. 

Hello Mickadam,

The Unity OE image recovery is reserved for customers with an active support contract. There is not a way to get the image without a warranty. If you don't know the OE version then you will need to contact support for assistance in getting the system backup and running.

@DELL-Sam L​ 

Hi,

Thank you

I've got theses informations

Hello Mickadam,

First thing that needs to be done is an ownership transfer of the system from the previous owner to your company. Here is the link for ownership transfer https://www.dell.com/support/assets-transfer/en-us