Random BSOD following fresh install and new motherboard

You apparently have a atheros based nic device.

This is the cause of your pain.
unfortunately I can't track down the atheros windows 7 drivers for you, I had it bookmarked but apparently they have changed their website ... significantly.

At any rate the driver for said device is clearly indicated as your problem causer.

Code:

Probably caused by : L1C62x64.sys ( L1C62x64+5e83 )

Followup: MachineOwner
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1: kd> !analyze -v
*******************************************************************************
*                                                                             *
*                        Bugcheck Analysis                                    *
*                                                                             *
*******************************************************************************

BAD_POOL_CALLER (c2)
The current thread is making a bad pool request.  Typically this is at a bad IRQL level or double freeing the same allocation, etc.
Arguments:
Arg1: 0000000000000007, Attempt to free pool which was already freed
Arg2: 000000000000109b, (reserved)
Arg3: 00000000040b000b, Memory contents of the pool block
Arg4: fffffa8007045e40, Address of the block of pool being deallocated

Debugging Details:
------------------


POOL_ADDRESS:  fffffa8007045e40 

FREED_POOL_TAG:  Hal 

BUGCHECK_STR:  0xc2_7_Hal 

CUSTOMER_CRASH_COUNT:  1

DEFAULT_BUCKET_ID:  VISTA_DRIVER_FAULT

PROCESS_NAME:  System

CURRENT_IRQL:  2

LAST_CONTROL_TRANSFER:  from fffff80002c0bbe9 to fffff80002addc40

STACK_TEXT:  
fffff880`02f1ba08 fffff800`02c0bbe9 : 00000000`000000c2 00000000`00000007 00000000`0000109b 00000000`040b000b : nt!KeBugCheckEx
fffff880`02f1ba10 fffff800`02a1c865 : fffffa80`09871a80 00000000`000000d0 00000000`00000000 fffffa80`08516350 : nt!ExDeferredFreePool+0x1201
fffff880`02f1bac0 fffff880`014f6831 : fffffa80`09936650 fffffa80`098b9bd8 fffffa80`06ea8680 00000000`00000000 : hal!HalPutScatterGatherList+0x115
fffff880`02f1bb20 fffff880`070f9e83 : fffffa80`098b9000 fffffa80`06ea8680 fffffa80`098b9000 00000000`00000000 : ndis!NdisMFreeNetBufferSGList+0x31
fffff880`02f1bb60 fffffa80`098b9000 : fffffa80`06ea8680 fffffa80`098b9000 00000000`00000000 00000000`00000000 : L1C62x64+0x5e83
fffff880`02f1bb68 fffffa80`06ea8680 : fffffa80`098b9000 00000000`00000000 00000000`00000000 00000000`00000000 : 0xfffffa80`098b9000
fffff880`02f1bb70 fffffa80`098b9000 : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : 0xfffffa80`06ea8680
fffff880`02f1bb78 00000000`00000000 : 00000000`00000000 00000000`00000000 00000000`00000000 fffff880`070fe800 : 0xfffffa80`098b9000


STACK_COMMAND:  kb

FOLLOWUP_IP: 
L1C62x64+5e83
fffff880`070f9e83 ??              ???

SYMBOL_STACK_INDEX:  4

SYMBOL_NAME:  L1C62x64+5e83

FOLLOWUP_NAME:  MachineOwner

MODULE_NAME: L1C62x64

IMAGE_NAME:  L1C62x64.sys

DEBUG_FLR_IMAGE_TIMESTAMP:  4aa0a7fd

FAILURE_BUCKET_ID:  X64_0xc2_7_Hal__L1C62x64+5e83

BUCKET_ID:  X64_0xc2_7_Hal__L1C62x64+5e83

Followup: MachineOwner
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good deal, based on the information in the crash dumps you attached it seems to be the only problem.
If something else goes bad please upload the newest minidump created by it.

I regret to inform you that it's the exact same thing causing the error.