BSOD System Service Exception atikmdag.sys

Well I recently reformatted my computer and I have narrowed down the problem to my Ati display driver.. whenever i update to the latest ATI driver and restart my computer it gets the bsod System Service Exception and atikmdag.sys and the only way to get back on is to run in safe mode and uninstall my ati drivers.. I have 2 ati radeon HD 5800's running on crossfire
i also took the "tests" when i uninstalled my display adapters because i cant access the internet through safe mode.
ive tried everything from reformatting again to updating my bios i am in desperate need of help would love if someone could fix this instead of me going to the geek squad tommorow
Is Windows 7 . . .
- x86 (32-bit) or x64 ? 64
- the original installed OS on the system? windows 7
- an OEM or full retail version? oem
- OEM = came pre-installed on system
- Full Retail = you purchased it from retailer

- What is the age of system (hardware)? 1 year
- What is the age of OS installation (have you re-installed the OS?) 1 day

These crashes were caused by memory corruption (probably a driver).
Please run these two tests to verify your memory and find which driver is causing the problem.

If you are overclocking anything reset to default before running these tests.
In other words STOP!!!


1-Memtest.

*Download a copy of Memtest86 and burn the ISO to a CD using Iso Recorder or another ISO burning program. Memtest86+ - Advanced Memory Diagnostic Tool

*Boot from the CD, and leave it running for at least 5 or 6 passes.

Just remember, any time Memtest reports errors, it can be either bad RAM or a bad motherboard slot.

Test the sticks individually, and if you find a good one, test it in all slots.

Any errors are indicative of a memory problem.

If a known good stick fails in a motherboard slot it is probably the slot.

RAM - Test with Memtest86+



2-Driver verifier

I'd suggest that you first backup your data and then make sure you've got access to another computer so you can contact us if problems arise. Then make a System Restore point (so you can restore the system using the Vista/Win7 Startup Repair feature).

In Windows 7 you can make a Startup Repair disk by going to Start....All Programs...Maintenance...Create a System Repair Disc - with Windows Vista you'll have to use your installation disk or the "Repair your computer" option at the top of the Safe Mode menu .

Then, here's the procedure:
- Go to Start and type in "verifier" (without the quotes) and press Enter
- Select "Create custom settings (for code developers)" and click "Next"
- Select "Select individual settings from a full list" and click "Next"
- Select everything EXCEPT FOR "Low Resource Simulation" and click "Next"
- Select "Select driver names from a list" and click "Next"
Then select all drivers NOT provided by Microsoft and click "Next"
- Select "Finish" on the next page.

Reboot the system and wait for it to crash to the Blue Screen. Continue to use your system normally, and if you know what causes the crash, do that repeatedly. The objective here is to get the system to crash because Driver Verifier is stressing the drivers out. If it doesn't crash for you, then let it run for at least 36 hours of continuous operation (an estimate on my part).

If you can't get into Windows because it crashes too soon, try it in Safe Mode.
If you can't get into Safe Mode, try using System Restore from your installation DVD to set the system back to the previous restore point that you created.

Driver Verifier - Enable and Disable


Further Reading
Using Driver Verifier to identify issues with Windows drivers for advanced users

Do what JMH says first but in addition I would try without crossfire.

I would also re-install the newest version of the video driver using this method.

When upgrading your graphic driver you MUST remove all traces of the current driver. In order to do that we recommend using

Phyxion.net - Driver Sweeper

When it is removed then download and install the fresh copy.