Win 7X64 BSOD

Please remove Avira from your system, third party antivirus software are known for causing BSODs and Avira is not an exeption.
Avira Antivirus Solution - Download AntiVir Removal Tool
Replace it by MSE instead (not known for BSOD causes):
http://www.microsoft.com/security_essentials

I suspect the Hard drive. Please run disk check and hard drive diagnostic (download the tool from HD manufacture website)
Disk Check
HD Diagnostic <---Instruction for HD test
Please download third party called memtestx86+, burn it to CD and let it run for at least 7 passes
Memory Diagnostics <---Instruction

nvrd32.sys was blamed in one dump file, it is your nVidia nForce RAID Driver, please download and install fresh copy of it.

Your graphic card was blamed in one of the dump. I would suggest you first download and install fresh copy of your graphic card with the directx as well
Download details: DirectX End-User Runtime


BUGCHECK SUMMARY:

Code:

BugCheck 4E, {99, 9e001, 2, 9e000}

Probably caused by : win32k.sys ( win32k!memset+b0 )

Followup: MachineOwner
---------
BugCheck 3B, {c0000005, fffff800031e7466, fffff8800390f150, 0}

Probably caused by : ntkrnlmp.exe ( nt!NtCreateFile+46 )

Followup: MachineOwner
---------
BugCheck 1A, {8886, fffffa800192aef0, fffffa80000008d0, 500}

Probably caused by : memory_corruption ( nt!MiUnlinkPageFromLockedList+298 )

Followup: MachineOwner
---------
BugCheck 4E, {99, 12801, 2, 127fb}

Probably caused by : memory_corruption ( nt!MiBadShareCount+4c )

Followup: MachineOwner
---------
BugCheck 23, {1805f1, 75c0, 0, 0}

Probably caused by : fastfat.SYS ( fastfat!FatCommonRead+892 )

Followup: MachineOwner
---------
BugCheck 24, {1904fb, fffff88002e34718, fffff88002e33f80, fffff880014ead97}

Probably caused by : Ntfs.sys ( Ntfs!NtfsQueryDirectory+8e7 )

Followup: MachineOwner
---------
BugCheck 4E, {99, ba7cf, 2, ba7c8}

Probably caused by : memory_corruption ( nt!MiBadShareCount+4c )

Followup: MachineOwner
---------
BugCheck 4E, {99, 41335, 2, 553d6}

Probably caused by : win32k.sys ( win32k!memset+b0 )

Followup: MachineOwner
---------
BugCheck 4E, {99, a7a19, 2, a6518}

Probably caused by : memory_corruption ( nt!MiBadShareCount+4c )

Followup: MachineOwner
---------
BugCheck D1, {10a039c, 2, 0, fffff8800108e774}

Unable to load image \SystemRoot\system32\DRIVERS\nvrd64.sys, Win32 error 0n2
*** WARNING: Unable to verify timestamp for nvrd64.sys
*** ERROR: Module load completed but symbols could not be loaded for nvrd64.sys
Probably caused by : nvrd64.sys ( nvrd64+f774 )

Followup: MachineOwner
---------
BugCheck A, {1, 8, 1, fffff80002e6cfe9}

Probably caused by : hardware ( nt!KiPageFault+260 )

Followup: MachineOwner
---------
BugCheck 50, {fffff87ff4c01650, 8, fffff87ff4c01650, 5}

Unable to load image \SystemRoot\system32\DRIVERS\atikmdag.sys, Win32 error 0n2
*** WARNING: Unable to verify timestamp for atikmdag.sys
*** ERROR: Module load completed but symbols could not be loaded for atikmdag.sys

Could not read faulting driver name
Probably caused by : atikmdag.sys ( atikmdag+36e7a9 )

Followup: MachineOwner
---------

Scan system file check please
SFC /SCANNOW Command - System File Checker

Let us know if you need help

Tuan

Please test your RAM, memory corruption was mentioned. The process running at the time of crash was MsMpEng.exe, which is part of Microsoft Window Defender.
Download a copy of Memtest86 and burn the ISO to a CD using Iso Recorder or another ISO burning program. Boot from the CD, and leave it running for at least 5 or 6 passes.

That's what I would like you to do before we get into investigating drivers

Code:

BugCheck 4E, {99, 3803b, 2, 3803a}

Probably caused by : memory_corruption ( nt!MiBadShareCount+4c )

Followup: MachineOwner
---------
PROCESS_NAME:  MsMpEng.exe

Run system file check please:
SFC /SCANNOW Command - System File Checker
as well as Disk Check

Regard,

Tuan

This one is pretty straight forward ... Memory Corruption... Download a copy of Memtest86 and burn the ISO to a CD using Iso Recorder. Boot from the CD, and leave it running for at least 5 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.

Code:

*******************************************************************************
*                                                                             *
*                        Bugcheck Analysis                                    *
*                                                                             *
*******************************************************************************

Use !analyze -v to get detailed debugging information.

BugCheck 4E, {99, 3803b, 2, 3803a}

Probably caused by : memory_corruption ( nt!MiBadShareCount+4c )

Followup: MachineOwner
---------

Be sure to let us know how it comes out..

Sounds like a compatibility issue. Let me summon our resident RAM expert.

He should be on in some hours, when he comes back online.