pc is constantly crashing

My pc is constantly crashing when I watch videos and when I run the wei. Im guessing its the video cards? I installed all latest updates for windows and drivers already and its stil bsod on me. Is it the video driver or my video cards? Everything I bought is new, I was thinking it might be my psu thats faulty? Anyways here are my specs.

Windows 7 Ultimate SP1 64-bit
AMD FX 8150 CPU
Gigabyte GA-990FXA-UD7 Motherboard
Corsair Dominator GT CMT8GX3M2A2000C9 DDR3 2000 MHz 2 x 4 GB Memory
AMD Radeon HD 6990 x 2 Crossfire Video Cards
Corsair Force Series 3 CSSD-F60GB3-BK SSD
OCZ ZX 1250W PSU
Lite-On IHES208 SATA BD Drive
Antec 12 Hundred Case

The only info you've given us to go on is "My pc is constantly crashing when I watch videos and when I run the wei", along w/ your system spec's. With only that info available to us, it's impossible to give you any sort of reasonable suggestions other than some troubleshooting tips. We'll need to know the EXACT error in the BSOD at the time of the crash. If you don't have that info available, then check the Event Viewer logs for any critical errors related to the time of the most recent BSOD. Start--> Type event viewer in the Start Search field, and hit ENTER. When you open Event Viewer and expand Critical, Application, or System logs - under "Windows Logs" (or look under "Summary of Administrative Events--> Event Type--> Critical)... double click the specific error so it opens in the Summary Page Events window. Next click on Copy--> Copy Details as Text in the RH pane, and paste the contents of the ClipBoard in this thread.

Have you run Memtest86+ or the Win7 built-in Memory Diagnostic tool? What's the current DRAM frequency, including timings and voltage? Is the controller that the SSD is connected to set to AHCI or IDE mode? What version of the CCC is installed, etc.? Basically... we need more info.