It would be better to keep a single thread rather than starting over with new ones - or posting multiple threads on the same subject.
It's not clear the GPU is at fault here. When reinstalling, did you:
1. Install the chipset drivers and reboot before going further?
2. Make sure you installed the drivers for the Intel GPU FIRST, before trying to install the AMD drivers? The system does not have a discrete AMD GPU - the AMD GPU is a co-processor for the Intel GPU, which handles all basic system video functions. Unless those drivers are in place, the AMD GPU is not going to function correctly.
3. Make sure you installed the Dell versions of the Intel and AMD drivers - NOT the ones available from Intel and AMD?