After installing ATI Catalyst driver release 8.12 for two or more ATI Radeon HD ™ 4850 graphics cards in a system with ATI CrossFireX™ technology, the system restarts and halts on a black screen. The black screen occurs prior to the loading of the desktop for the Windows Vista 64-bit or Windows Vista 32-bit operating systems.
This issue ONLY occurs when two or more ATI Radeon HD 4850 graphic cards are installed in the system with ATI CrossFireX technology. One single ATI Radeon HD 4850 card will not encounter this issue.
The following hotfix may help resolve the issue:
Catalyst 8.12 Hotfix for Windows Vista 64-bit Edition
Note: The hotfix driver is only necessary if two or more ATI Radeon HD 4850 graphic cards are installed in the system with ATI CrossFireX technology
The issue applies to the following products:
* ATI Catalyst release 8.12
* 2 or more installed ATI Radeon™ HD 4850 series graphic cards in a system with ATI CrossFireX technology
* Windows Vista 64-Bit Edition
Here's other similar drivers that are different versions or releases for different operating systems: