First install the latest HD 7850 for Windows 7 from here: Radeon™ Software Adrenalin Edition 18.9.3 Release Notes | AMD .
If you continue to get a black screen, try a previous AMD driver that you know that worked from here: AMD Radeon™ HD 7850 Previous Drivers | AMD .
If all fails, uninstall the AMD driver and just try to install the HD 7850 graphic driver manually via Device Manager.
Use this basic procedure to install and uninstall your current AMD Driver:
install AMD driver:
1) Download the correct AMD Full Set of drivers from AMD Support. Make sure your Windows is fully updated via Windows Update. Windows Must be fully updated because the latest AMD Drivers requires all the latest "Optional" and "Recommended" updates to be installed.
2) Use Windows Uninstall to uninstall current AMD driver and software and disconnect the internet from your computer. Then use DDU (Display Driver Uninstaller) Display Driver Uninstaller (DDU) from Wagnardsoft Forum in Safe Mode. This will eliminate all traces of the AMD driver and software from your computer.
Delete C: \ AMD folder from the Root Directory. Reboot
3) Go to Device Manager and click "Display Adapter" and make sure you are on the MS Basic Display Adapter. If not, uninstall the AMD driver using Properties.
4) Try reinstalling the AMD FULL SET OF DRIVERS that you have downloaded manually. Make sure you disable the Internet to prevent Windows from installing a newer version. So configure windows to prevent it from updating drivers via windows update. So it has been mentioned to disable any anti-virus programs before installing AMD Drivers.
5) If the new AMD drivers installs and works correctly, delete again the C: \ AMD folder from the root directory. To save space on the HDD.
6) Enable both the Internet and Anti-Virus program (if applicable).
7) Go back to Device Manager and check your GPU card driver is working and identified correctly.
IF you are able to reach Windows Desktop with the HD 7850 than try the following to check the GPU card:
See if you get the same results in a different computer .
Stress the GPU card with Error using OCCT which is a free diagnostic program. Need to run it in Full Screen and check the Error box for an hour if it last that long. See what the results are.
You can download OCCT here : Download .
OCCT is about the only free diagnostic program that also test your PSU which may be a good idea if you see during the GPU test the outputs to the PSU are not within 5% tolerances.
