System Freeze up and SideBySide Error

Hello buddies, it's me again.
It's a week now that my PC - usually in the morning, but not only - freezes: the mouse stops and I only can reset. Then the computer starts normally, only 1 time did a check disk on a secondary drive.

I ws thinking about my mobo, it's not so young now so maybe needs an update. But I cannot find anything for Seven and I cannot understand why this problem happens only some time.
My mobo is an Asus P5W DH Deluxe and in HERE no Seven
My last event log :

Log Name: System
Source: Microsoft-Windows-Kernel-Processor-Power
Date: 22/11/2010 09:43:03
Event ID: 6
Task Category: (6)
Level: Error
Keywords:
User: SYSTEM
Computer: LioSeven-PC
Description:
Some processor performance power management features have been disabled due to a known firmware problem. Check with the computer manufacturer for updated firmware.
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
<System>
<Provider Name="Microsoft-Windows-Kernel-Processor-Power" Guid="{0F67E49F-FE51-4E9F-B490-6F2948CC6027}" />
<EventID>6</EventID>
<Version>0</Version>
<Level>2</Level>
<Task>6</Task>
<Opcode>0</Opcode>
<Keywords>0x8000000000000000</Keywords>
<TimeCreated SystemTime="2010-11-22T13:43:03.198422300Z" />
<EventRecordID>50725</EventRecordID>
<Correlation />
<Execution ProcessID="4" ThreadID="52" />
<Channel>System</Channel>
<Computer>LioSeven-PC</Computer>
<Security UserID="S-1-5-18" />
</System>
<EventData>
</EventData>
</Event>

and also this in an other day

Problem signature:
Problem Event Name: BlueScreen
OS Version: 6.1.7600.2.0.0.256.48
Locale ID: 1040

Additional information about the problem:
BCCode: 124
BCP1: 0000000000000000
BCP2: FFFFFA8008BE2038
BCP3: 0000000000000000
BCP4: 0000000000000000
OS Version: 6_1_7600
Service Pack: 0_0
Product: 256_1

Files that help describe the problem:
C:\Windows\Minidump\111810-92680-01.dmp
C:\Users\LioSeven\AppData\Local\Temp\WER-105550-0.sysdata.xml

and here all my dump file from the beginning of all my problems.

I've searched every where, but when the computer is running, all is normal, no slowdown no problem at all.
I noticed that when the PC freezes, the temperature begin to go up.

Hope you guys can help me :)
Thanks
Lio

Here you go me again

Your .dmp file shows a stop error of 0x124 which is a general hardware error .. A "stop 0x124" is fundamentally different to many other types of bluescreens because it stems from a hardware complaint. Stop 0x124 minidumps contain very little practical information, and it is therefore necessary to approach the problem as a case of hardware in an unknown state of distress. You can read more on this error and what to try here... Stop 0x124 - what it means and what to try Stop 0x124 - what it means and what to try

Thanks so much for your reply :)
I've read the page you give me, and my conclusion is:
My pc is not overclocked. All the four RAM seems to be perfect with the check program. The HDDs are ok, excluding one drive connected on EIDE (the only one, the other 3 are SATA) that sometimes disappear after the PC goes in sleeping mode.
I don't know why, that drive is recognized as USB drive
(Sorry for my bad english, is not my native language)
Regarding the OS and all the software, I'm pretty sure that all it's perfect.
For the cooling, the temperature is very good.
I was thinking about a BIOS upgrade, but my mobo is not recent and there is not any upgrade for Seven and I don't like to flash the BIOS
For sure there is a problem, but why only sometimes?
Can you suggest to a poor woman what she can try?
Thanks
Lio

Start with this for 7 passes
Then test each slot with a known good stick
Download memtest86 and test RAM
www.sevenforums.com/tutorials/105647-ram-test-memtest86.html