After some problems with Windows 10, I decided to come back to Windows 7, in hope that I can resolve my problems, but no. After installing the correct drivers for my system, I installed my driver for GPU, a AMD Radeon HD7850. I have to mention that before that, in Device Manager at Display adapters, I get a Standard VGA graphics adapter instead of my gpu. After I install the driver, the name changes to ATI Radeon HD series, but when I restart it to optimize the driver, I get the Starting Windows sign, and then infinite black screen. I only got to shut down my PC from button, and start it over. Now I get a message whether I want to Launch Start Up Repair or start normally. If I press Launch repair it works, but only if I restore my pc from past, which means deleting latest changes made. In the Diagnosis and repair details it appears that "A recent driver installation or upgrade may be preventing the system from starting". After the repair is done, it restarts it self and it works, but the gpu driver is erased. I mention that the gpu's fans are on, and my monitor is connected to it, so I think it shouldn't have problems. I hope you can help me. Thanks.
Gigabyte z87m-d3h motherboard
amd radeon hd7850
I tried different things, such as updating the BIOS, changing the position of RAMs, putting the gpu in the 2nd PCIe slot, installing a new Windows. Nothing worked...