If you right-click an empty area of the desktop select the Screen Resolution option and make sure it's set to the native (optimal) resolution for your specific monitor. Check the monitor's manual for its native resolution.

If that doesn't help, manually set a System Restore point, to be safe. Then open Device Manager and roll back the ATI video driver to the previous version. And if that still doesn't help, try rolling back the Intel HD Graphics driver too.

And if that still doesn't help,  read this and try at your own risk:

community.amd.com/.../184967

This card is legacy.   Directx June 2010 as well as the Legacy Driver and DOTNET 2.0 3.5 is required for CATALYST CONTROL CENTER.  Automatically Detect and Install Your Driver DOES NOT and WILL NOT ever work with LEGACY cards.

https://www.microsoft.com/en-us/download/details.aspx?id=8109

You download the file and extract to a FOLDER then run dxsetup.exe

https://docs.microsoft.com/en-us/dotnet/framework/install/dotnet-35-windows-10

You will have to use the Legacy Drivers for this card or get a newer one.

• Windows 7 (32-b​​it | ​64-bit)

It isn't compatible, and that is precisely the problem: support.amd.com/.../Win10-Driver-Support.aspx

You're going to need to buy a new card for your system to work correctly. I had the same problem with an HD 4670 and, no matter what you do, you won't get the text and graphics to look good. I tried everything at the time I installed Windows 10, including the legacy drivers, and it simply was no good. I ended up getting a GTX 750, and that worked fine. But, there are many, many compatible choices, both AMD and nVidia based.

Fhill your answer is completely WRONG.  I am using a radeon 3450 with Windows 10 on an optiplex 760 with the legacy drivers to post this message.  Catalyst Control Center and Dual monitors and Directx 9 and 10 are working just fine.

The card works fine in windows 7 8 and 10 with the LEGACY WDDM 1.0 driver. He does not have to buy a new card but he does have to reinstall DOTNET 2.0 3.5 and Legacy direct play from control panel while online because these components are downloaded not installed by default.  This is also why DIRECTX June 2010 is also required.

• Windows 7 (32-b​​it | ​64-bit)
   
  Directx June 2010 must also be installed as well as legacy direct play.
  
   
  AMD Radeon™ HD 4000 Series products and older are not certified to support Windows Display Driver Model (WDDM) 1.2 or higher and therefore, do not have driver support for Windows® 10.  This means in english these are cards that only support Directx 9 and Directx10.   Windows 7 and 8 are directx 11 and windows 10 is directx 12.  WDDM 1.0 drivers are VISTA Drivers.
  
  This is why Optiplex GX620 with INTEL Graphics works fine with windows 10 and the WDDM 1.0 Vista Drivers for Video and Audio.
  
   

  Windows 10 system requirements

  Here's what it takes to Run Windows 10 on your PC or tablet:

  • Latest OS: Make sure you're running the latest version—either Windows 7 SP1 or Windows 8.1 Update.
  • Processor: 1 gigahertz (GHz) or faster processor or SoC
  • RAM: 1 gigabyte (GB) for 32-bit or 2 GB for 64-bit
  • Hard disk space: 16 GB for 32-bit OS or 20 GB for 64-bit OS
  • Graphics card: DirectX 9 or later with WDDM 1.0 driver
  • Display: 800 x 600

  Windows® 10 will install the default Microsoft®​Basic Display Driver (MBDD) for these graphics adapters. MBDD provides basic display functionality (low resolutions and color) on a single monitor but DOES NOT support:

  • Display scaling control
  • Multiple displays
  • Display rotation
  • Video capture
  • Power settings
  • VSync control
  • Brightness control on integrated display panels
  • AMD Catalyst™ Control Center  (A DOTNET 2.0 application)