For those of you suffering from immediate lockups when using MSI Afterburner with Crossfire, you need to disable ULPS through regedit. Latest ATI drivers enable this by default and causes conflicts with Afterburner. Here is step by step. Click Start, Accessories, Run, when the run box opens, type regedit and launch. Now, follow these screen shots. Item 1, double click and open HKEY_LOCAL_MACHINE
Item 2, double click and open SYSTEM
Item 3, double click and open ControlSet001
Item 4, double click and open Control
Item 5, double click and open Class
Item 6, double click and open {4D36E968-E325-11CE-BFC1-08002BE10318}
Item 7, single click 0000
Item 8, move to the right column and scroll down to EnableUlps. Right click, then left click modify and then change the value data from a 1 to a 0.
Repeat Items 7 and 8 for 0001, 0002, 0003.
Exit regedit and reboot. Enjoy MSI Afterburner!.