It is best to use Dell's own AMD Driver if it isn't too out-dated.
Deleted my info which was not applicable to your Dell GPU card.
Here is Dell's Support download page for your Laptop: https://www.dell.com/support/home/en-us/product-support/product/precision-m4800-workstation/drivers
I don't see any AMD Drivers for a consumer R9 M200X GPU card instead I see AMD Professional GPU card drivers.
Possibly the above M4800 Laptop is a newer model than the one you have or a different M4800 model.
Download and run GPU-Z which will show what GPU card you have installed.
Please read my next 2 replies concerning your Dell's Laptop GPU card.