Initially I thought it might have been a driver (expecting the usual ati) then I considered the new ram, but it passes every test I can throw at it so I'm back at square one i.e. lack of windows knowledge hoping I haven't corrupted windows 
Debugging tool produced this, can anyone expand on it
I was planning on reinstalling this week anyway, just don't want to recreate my problem.

Debugging tool produced this, can anyone expand on it
Code:
Microsoft (R) Windows Debugger Version 6.12.0002.633 AMD64
Copyright (c) Microsoft Corporation. All rights reserved.
Loading Dump File [C:\Windows\Minidump\093011-31871-01.dmp]
Mini Kernel Dump File: Only registers and stack trace are available
Symbol search path is: SRV*C:\SymCache*http://msdl.microsoft.com/download/symbols
Executable search path is:
Windows 7 Kernel Version 7601 (Service Pack 1) MP (4 procs) Free x64
Product: WinNt, suite: TerminalServer SingleUserTS Personal
Built by: 7601.17640.amd64fre.win7sp1_gdr.110622-1506
Machine Name:
Kernel base = 0xfffff800`02e16000 PsLoadedModuleList = 0xfffff800`0305b670
Debug session time: Fri Sep 30 16:01:40.802 2011 (UTC + 1:00)
System Uptime: 0 days 6:18:04.223
Loading Kernel Symbols
...............................................................
................................................................
......................................
Loading User Symbols
Loading unloaded module list
.....
*******************************************************************************
* *
* Bugcheck Analysis *
* *
*******************************************************************************
Use !analyze -v to get detailed debugging information.
BugCheck 1E, {ffffffffc0000005, fffff960000de2de, 0, ffffffffffffffff}
Probably caused by : partmgr.sys ( partmgr!PmGlobalDispatch+9f )
Followup: MachineOwner
---------
0: kd> !analyze -v
*******************************************************************************
* *
* Bugcheck Analysis *
* *
*******************************************************************************
KMODE_EXCEPTION_NOT_HANDLED (1e)
This is a very common bugcheck. Usually the exception address pinpoints
the driver/function that caused the problem. Always note this address
as well as the link date of the driver/image that contains this address.
Arguments:
Arg1: ffffffffc0000005, The exception code that was not handled
Arg2: fffff960000de2de, The address that the exception occurred at
Arg3: 0000000000000000, Parameter 0 of the exception
Arg4: ffffffffffffffff, Parameter 1 of the exception
Debugging Details:
------------------
EXCEPTION_CODE: (NTSTATUS) 0xc0000005 - The instruction at 0x%08lx referenced memory at 0x%08lx. The memory could not be %s.
FAULTING_IP:
win32k!MultiUserGreCleanupHmgOwnRemoveAllLocks+72
fffff960`000de2de 44896008 mov dword ptr [rax+8],r12d
EXCEPTION_PARAMETER1: 0000000000000000
EXCEPTION_PARAMETER2: ffffffffffffffff
READ_ADDRESS: GetPointerFromAddress: unable to read from fffff800030c5100
ffffffffffffffff
ERROR_CODE: (NTSTATUS) 0xc0000005 - The instruction at 0x%08lx referenced memory at 0x%08lx. The memory could not be %s.
BUGCHECK_STR: 0x1E_c0000005
CUSTOMER_CRASH_COUNT: 1
DEFAULT_BUCKET_ID: VISTA_DRIVER_FAULT
PROCESS_NAME: Steam.exe
CURRENT_IRQL: 0
LAST_CONTROL_TRANSFER: from fffff80002ede588 to fffff80002e92c40
STACK_TEXT:
fffff880`09703858 fffff800`02ede588 : 00000000`0000001e ffffffff`c0000005 fffff960`000de2de 00000000`00000000 : nt!KeBugCheckEx
fffff880`09703860 fffff800`02e922c2 : fffff880`09704038 00000000`00017b68 fffff880`097040e0 00000000`00000fcf : nt! ?? ::FNODOBFM::`string'+0x4977d
fffff880`09703f00 fffff800`02e90bca : 00000000`000016f4 00000000`00000001 fffffa80`08c66ee0 fffff960`000d5290 : nt!KiExceptionDispatch+0xc2
fffff880`097040e0 fffff960`000de2de : 00000000`00000000 00000000`00000001 00000000`00000001 00000000`00000001 : nt!KiGeneralProtectionFault+0x10a
fffff880`09704270 fffff960`000dda0b : 00000000`00000000 fffff880`0970461f 00000000`00000998 fffff900`c077c010 : win32k!MultiUserGreCleanupHmgOwnRemoveAllLocks+0x72
fffff880`097042a0 fffff960`000d50f0 : 00000000`00000998 fffff880`09704600 fffff900`c077c010 fffff960`00000000 : win32k!NtGdiCloseProcess+0x11b
fffff880`09704300 fffff960`000d4823 : 00000000`00000000 fffff880`097046a0 fffffa80`09882b60 00000000`00000000 : win32k!GdiProcessCallout+0x200
fffff880`09704380 fffff800`03168a81 : 00000000`00000000 00000000`00000000 00000000`00000000 fffffa80`09882b00 : win32k!W32pProcessCallout+0x6b
fffff880`097043b0 fffff800`0314c09d : 00000000`40010004 00000000`00000001 fffff8a0`78457300 fffffa80`0994eb60 : nt!PspExitThread+0x4d1
fffff880`097044b0 fffff800`02e863fa : fffff8a0`c0000034 fffff800`03406ae7 00000000`00920090 00000000`0018a6ec : nt!PsExitSpecialApc+0x1d
fffff880`097044e0 fffff800`02e86740 : 00000000`003cadd8 fffff880`09704560 fffff800`0314c010 00000000`00000001 : nt!KiDeliverApc+0x2ca
fffff880`09704560 fffff800`02e865db : 00000000`003cadd8 00000000`00000000 fffff800`0314c010 00000000`00000000 : nt!KiInitiateUserApc+0x70
fffff880`097046a0 00000000`755a1b68 : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : nt!KiApcInterrupt+0x10b
00000000`0018c5c8 fffff800`02e8a210 : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : 0x755a1b68
fffff880`09704aa0 fffffa80`07a9ece0 : fffff880`00f940af fffffa80`0a305bd0 00000000`ffffffff fffffa80`0a305e98 : nt!KiCallUserMode
fffff880`09704aa8 fffff880`00f940af : fffffa80`0a305bd0 00000000`ffffffff fffffa80`0a305e98 fffff880`097053f0 : 0xfffffa80`07a9ece0
fffff880`09704ab0 00000000`00000007 : 402832b3`33333333 00000000`00000000 00000000`00000000 00000000`00000000 : partmgr!PmGlobalDispatch+0x9f
fffff880`09704ae0 402832b3`33333333 : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : 0x7
fffff880`09704ae8 00000000`00000000 : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : 0x402832b3`33333333
STACK_COMMAND: kb
FOLLOWUP_IP:
partmgr!PmGlobalDispatch+9f
fffff880`00f940af 8bf0 mov esi,eax
SYMBOL_STACK_INDEX: 10
SYMBOL_NAME: partmgr!PmGlobalDispatch+9f
FOLLOWUP_NAME: MachineOwner
MODULE_NAME: partmgr
IMAGE_NAME: partmgr.sys
DEBUG_FLR_IMAGE_TIMESTAMP: 4ce792c0
FAILURE_BUCKET_ID: X64_0x1E_c0000005_partmgr!PmGlobalDispatch+9f
BUCKET_ID: X64_0x1E_c0000005_partmgr!PmGlobalDispatch+9f
Followup: MachineOwner
---------
I was planning on reinstalling this week anyway, just don't want to recreate my problem.

Not meaning to be rude thoug, have you eer actaully tries to use, or simply try to make work, samsungs crappy dos estool?