Windows 8 Random freezes and BSODs

Hi, i've been getting random freezes of my Acer Aspire laptop recently and a few BSODs, too. I can't seem to understand why.
Here's the last minidump of the windbg tool that I can get (the dumping process didn't move past 0% progress today when I got the BSOD and so I have no dump from today).
I suspect it's a hardware issue but don't know what to do.
I have replaced the original DVD-drive with an SSD disk, the first one was faulty so I'm wondering if this one is faulty too. But the symptoms are different this time round, so I suspect that may not be it.
Any help would be greatly appreciated.
Jan



Microsoft (R) Windows Debugger Version 6.2.9200.20512 AMD64
Copyright (c) Microsoft Corporation. All rights reserved.




Loading Dump File [C:\Windows\Minidump\020813-24609-01.dmp]
Mini Kernel Dump File: Only registers and stack trace are available


Symbol search path is: SRV*c:\symbols*http://msdl.microsoft.com/download/symbols
Executable search path is:
Windows 8 Kernel Version 9200 MP (4 procs) Free x64
Product: WinNt, suite: TerminalServer SingleUserTS
Built by: 9200.16461.amd64fre.win8_gdr.121119-1606
Machine Name:
Kernel base = 0xfffff801`52016000 PsLoadedModuleList = 0xfffff801`522e0a80
Debug session time: Fri Feb 8 13:24:13.306 2013 (UTC + 2:00)
System Uptime: 8 days 3:46:29.310
Loading Kernel Symbols
...............................................................
................................................................
...............................
Loading User Symbols
Loading unloaded module list
..................................................
*******************************************************************************
* *
* Bugcheck Analysis *
* *
*******************************************************************************


Use !analyze -v to get detailed debugging information.


BugCheck E1, {fffff8015207c3b4, 1, fffffa800554f260, fffffa800554f260}


Probably caused by : ntkrnlmp.exe ( nt!IopProcessWorkItem+0 )


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


WORKER_THREAD_RETURNED_AT_BAD_IRQL (e1)
Arguments:
Arg1: fffff8015207c3b4, address of worker routine (do ln on this to find guilty driver)
Arg2: 0000000000000001, IRQL returned at (should have been 0, but isn't).
Arg3: fffffa800554f260, workitem parameter
Arg4: fffffa800554f260, workitem address


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




FAULTING_IP:
nt!IopProcessWorkItem+0
fffff801`5207c3b4 48895c2410 mov qword ptr [rsp+10h],rbx


CUSTOMER_CRASH_COUNT: 1


DEFAULT_BUCKET_ID: WIN8_DRIVER_FAULT


BUGCHECK_STR: 0xE1


PROCESS_NAME: System


CURRENT_IRQL: 1


LAST_CONTROL_TRANSFER: from fffff801522139d1 to fffff80152091340


STACK_TEXT:
fffff880`0bc92cb8 fffff801`522139d1 : 00000000`000000e1 fffff801`5207c3b4 00000000`00000001 fffffa80`0554f260 : nt!KeBugCheckEx
fffff880`0bc92cc0 fffff801`52038551 : fffff880`00000000 00000000`00000080 fffff801`520c93d0 fffffa80`0c269040 : nt! ?? ::FNODOBFM::`string'+0x4c082
fffff880`0bc92d50 fffff801`52076dd6 : fffff880`018cf180 fffffa80`0c269040 fffffa80`04174b00 fffffa80`0419d940 : nt!PspSystemThreadStartup+0x59
fffff880`0bc92da0 00000000`00000000 : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : nt!KiStartSystemThread+0x16




STACK_COMMAND: .bugcheck ; kb


FOLLOWUP_IP:
nt!IopProcessWorkItem+0
fffff801`5207c3b4 48895c2410 mov qword ptr [rsp+10h],rbx


SYMBOL_NAME: nt!IopProcessWorkItem+0


FOLLOWUP_NAME: MachineOwner


MODULE_NAME: nt


IMAGE_NAME: ntkrnlmp.exe


DEBUG_FLR_IMAGE_TIMESTAMP: 50ab0e64


BUCKET_ID_FUNC_OFFSET: 0


FAILURE_BUCKET_ID: 0xE1_nt!IopProcessWorkItem


BUCKET_ID: 0xE1_nt!IopProcessWorkItem


Followup: MachineOwner
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