This message was posted on behalf of Intel Corporation
In regard to your inquiry, according to the specifications, the laptop works with both Intel® graphics and NVIDIA® GeForce® discrete graphics, here is the link to confirm that information:
When the laptop works with two different graphics controllers we always recommend to use the drivers provided by the manufacturer.
On the following link you will find further information about switchable graphics, please read the last question:
Please try to install Windows one more time, and then try the drivers provided by Dell, just in case on the following link you will be able to find them, you can always change the operating system depending if you are going to use Windows® 7 or 10:
Additionally, since the laptop also works with Intel® HD graphics 5500 controller, on the following link you will find the latest graphics drivers available for it, in there you can also choose between those operating systems:
Also there are "inbox" drivers, that get installed when you install Windows or when you do a Windows update, as an option you can try to use those drivers as well.
Another option will be to get in contact with Dell directly to check if maybe a BIOS update is necessary in this case, they will be able to provide further details on that matter and also for them to confirm if there might be a hardware problem with the laptop, and in that case to provide warranty assistance:
Dell’s phone number: 1 800-624-9897
Dell’s support site: http://www.dell.com/support/home/ae/en/aedhs1/product-support/product/inspiron-15-5558-laptop/diagnose
Please let me know the results of trying the steps above.
Any further questions, please let me know.