Replacing the old version of atikmdag.sys with an updated copy.
Make sure you have your ATi drivers updated. If you are unsure of what you are doing, make sure to have someone who has experience in modifying system files. Navigate to your C:Windows\System32\drivers (assuming Windows is installed in C: with default path). Look for atikmdag.sys and hover your mouse over it. If this driver version number is different from the latest driver version, it needs to replaced. So what you do is:
1. Download the latest driver version and extract the contents of the .exe file (this should happen when
you double click on the .exe, if not, use 7zip to extract it).
2. Rename your current atikmdag.sys file to atikmdag.sys.old.
3. Look for atikmdag.sy_ in the folder where you extracted the latest drivers.
4. Copy atikmdag.sy_ to WindowsSystem32drivers folder.
5. Open command prompt in Administrator mode (start menu->programs->accessories->right click
command prompt->Run as Administrator).
6. Navigate to your Windows\System32\drivers folder. (example cd C:\Windows\System32\drivers)
7. Type expand atikmdag.sy_ atikmdag.sys
8. Reboot computer.
For most people, this has solved the problem completely.
