Windows 7: Stop 0x124 error on Win7 RTM x86 Ultimate machine

I keep getting this STOP 0x124 errors. It is a Hp slimline s3500f series desktop with 4GB RAM. I tried to debug a bit and it looks like I need to decipher some information out of the MCi_Status field and I am lost here. Please help me here to find out if this indeed a Hardware issue. I am also attaching the log file of the kd debugging output.

1: kd> !analyze -v=20
*******************************************************************************
* *
* Bugcheck Analysis *
* *
*******************************************************************************
WHEA_UNCORRECTABLE_ERROR (124)
A fatal hardware error has occurred. Parameter 1 identifies the type of error
source that reported the error. Parameter 2 holds the address of the
WHEA_ERROR_RECORD structure that describes the error conditon.
Arguments:
Arg1: 00000000, Machine Check Exception
Arg2: 86706024, Address of the WHEA_ERROR_RECORD structure.
Arg3: b6218000, High order 32-bits of the MCi_STATUS value.
Arg4: 00000175, Low order 32-bits of the MCi_STATUS value.
Debugging Details:
------------------
PEB is paged out (Peb.Ldr = 7ffdc00c). Type ".hh dbgerr001" for details
PEB is paged out (Peb.Ldr = 7ffdc00c). Type ".hh dbgerr001" for details
BUGCHECK_STR: 0x124_AuthenticAMD
DEFAULT_BUCKET_ID: VISTA_DRIVER_FAULT
PROCESS_NAME: mencoder.exe
CURRENT_IRQL: 1f
STACK_TEXT:
807c88cc 83037f3f 00000124 00000000 86706024 nt!KeBugCheckEx+0x1e
807c8908 82ce7f04 866f8771 86706024 82c814f0 hal!HalBugCheckSystem+0xab
807c8938 830381f1 866fba88 83045e40 00000001 nt!WheaReportHwError+0x230
807c8a4c 830382e3 866fba88 866fbad8 00000000 hal!HalpMcaReportError+0x3b
807c8a70 8303854f 00000000 866fbad8 807c8b90 hal!HalpMceHandler+0x8b
807c8a80 8302e5f5 00000000 8bc5c2f4 807baaa8 hal!HalpHandleMachineCheck+0x3b
807c8b90 8302b261 00000000 807c3750 807babd0 hal!HalpMcaExceptionHandler+0x87
807c8b90 006d5280 00000000 807c3750 807babd0 hal!HalpMcaExceptionHandlerWrapper+0x89
WARNING: Frame IP not in any known module. Following frames may be wrong.
00000047 00000000 00000000 00000000 00000000 0x6d5280



STACK_COMMAND: kb
FOLLOWUP_NAME: MachineOwner
MODULE_NAME: hardware
IMAGE_NAME: hardware
DEBUG_FLR_IMAGE_TIMESTAMP: 0
FAILURE_BUCKET_ID: 0x124_AuthenticAMD_PROCESSOR_CACHE
BUCKET_ID: 0x124_AuthenticAMD_PROCESSOR_CACHE
Followup: MachineOwner
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See this post by a former expert on this stop error.. -=> here