Atikmdag error mostly appears while playing heavy graphical games. Error format: Display driver atikmdag stopped responding and has successfully recovered Here are some simple steps that will help you to fix this error:

Download and Replace Atikmdag File
Downloading and replacing the old atikmdag file with the new one may fix the atikmdag error. To do so follow the steps below:
Fix Broken Windows Registry
PC errors normally appear when the Windows registry is broken. atikmdag error may also appear due to this reason. Simple way of fixing broken registry is to install a Registry Cleaning tool. It automatically detects and fix the broken entries. Click Here for Registry Scan.
Uninstall KB952287
Many PC users face atikmdag error after installing KB952287 hotfix. Uninstalling it may reoslve the issue. Follow the steps below for uninstallation.
Use Windows Deafult Drivers
Atikmdag error can also been fixed by using Windows default drivers. Uninstall all the installed drivers and restart your PC. On logon Windows will automatically install the default drivers.