It's a bit late now, but for future reference to eliminate a driver
Firstly Download and install Driver Sweeper: Guru3D - Driver Sweeper
Then Uninstall the driver from within device manager, making sure you select the "delete the driver software for this device"
Next go to add/remove programs and uninstall ATI Catalyst install manger.
Re-boot into Safe mode and run Driver Sweeper (run as admin) to clean all ATI references.
Delete any remaining ATI folders, ie C:\ATI ; C:\Program Files (x86)\ATI Technologies ; C:\Program Files\ATI Technologies
Re-boot normally and install the catalyst suite.
If the BSOD's still occur, it's likely the issue lies elsewhere. Either the codec pack, it's player or your sound card.
VLC is a good player that handles pretty much everything out of the box without using codec packs: VLC media player - Overview