Windows rebooting repeatedly at startup, later every few hours

[lami58]

I'm in Europe.
I've read all the typical advice for automatic rebooting.
It's early spring and there is no overheating of my CPU.
I've uninstalled the Akamai software (provided with Adobe Flash Player), a possible cause of the reboots.
I've reinstalled the Flash Player software.
The problem persists, however.
My computer is 6 years old, Windows XP, no repairs during that time.
I just can't put my finger on the problem.
I've attached two dumps from today and three from Friday when the real problems started - I mean 5-6 automatic reboots, especially at startup, which sometimes end in success and sometimes in a still screen of uncompleted startup.
What do you think?

 

[Tmagic650]

What antivirus program are you using? Looks like a Norton product. Is XP updated to Service Pack 3 and beyond?

 

[lami58]

the following

Norton Internet Security 2012 (which wants the Windows Firewall to be disabled) and Windows XP Service Pack 3

 

[Tmagic650]

Remove Norton and install Microsoft Security Essentials (MSE):
http://windows.microsoft.com/en-US/windows/products/security-essentials

Before you complain about having to remove Norton, be aware that it is most likely contributing to your computers instability... Let MSE control the Windows firewall

 

[lami58]

Norton

I've been using Norton products on this computer since 2006 without problems.

 

[Tmagic650]

I haven't used Norton since 2006! I told you that Norton is contributing to your computers instability. If you want to leave it that way, so be it