Sometimes the latest drivers from NVIDIA or AMD can cause issues that were not present in an older version of the drivers.
While these are normally fixed in a later version it can be useful to uninstall the new driver and do a fresh install of the older working driver until these issues are resolved.
It can also be worthwhile doing a fresh installation of your current driver if you have updated to the latest driver, but are still having problems.
There are two ways to do this:
1. Do a clean installation using the AMD or NVIDIA installer.
NVIDIA: To do this you will need to download the NVIDIA driver you wish to install. Run this installation and select "Custom installation" asked you will need to check the box to "Perform clean install" Full instructions can be found here: http://nvidia.custhelp.com/app/answers/detail/a_id/2900/
AMD: You will need to uninstall the AMD Catalyst Install Manager from Programs and Features in the control panel and then reinstall the driver version that you wish to run. Full instructions can be found here: http://support.amd.com/en-us/kb-articles/Pages/GPU57RemoveOldGraphicsDrivers.aspx
2. Use a 3rd party utility such as Display Driver Uninstaller.
To use Display Driver uninstaller please follow the guide here:
http://www.guru3d.com/files-details/display-driver-uninstaller-download.html
If you are still having problems after doing a fresh install of drivers that you knew were working previously, then please do let us know. You can open a support ticket using the button below.