Here I answer to the questions plus some thoughts I have.
Since this is a trouble that I am having for over 2 months, there are a several things I think it could be.
1 - Virus: I had been dealing with this issue in this forum, thread "PC Random Reboot", it had some malware and was fixed but the trouble remains the same. The last MB report done it today after the reboot is attached.
2 - Dust/poor cooling/hardware plus software.
I run the PC in Win XP, windows 7 very rare because of software compatibility.
PC Cleaning. I opened the case and with a brush cleaned all the dust in the MB, CPU fan, fan case and any other place I had access to. I even removed the RAM stick and cleaned the contact edge.
I attach the SpeedFan screen as requested.
3 - Since my last post I kept on searching the net and found some threads with similar problems and it gave me more clues where the problem may be. So I went to:
My Computer ==> Manage ==> Event Viewer ==> and select System because I think the trouble could be related to some system files.
I attach one of two pics from last reboot, this morning at 7:11:21 or 7:11:22, these are the times I have failures reported, both indicates:
Source: Service Control Manager
Event ID: 7022
Out of these three option, I think the answer is in the last one. The problem is how to fix this, can anyone help me?