HI,
After update my kernel by software updater my linux gets reset (= like I pressed reset button on the case) Time to Time, usually after 5 to 10 minutes passed from boot time in a random fashion (no matter if there is a user logged on and working with the OS or not or no matter what ever action in progress)? I can not name a specific action causing this!

the crazy thing is that some times this happens when the system has successfully booted to X Window and is showing the login screen waiting for the first logon. I am Like what!!! because the system cleanly booted and there were no activity for at least 5 mins and no user had logged on after boot (so there is no chance the problem is caused by a action initiated by a user).
I am usgin FC6 that boots to X Windows Automatically.

I dont know what is wrong?

I would turn off power management in the BIOS and do the same with the kernel, i think its noapic
Also run memcheck, available on just about any live CD from the GRUB menu.
Speaking of which run a live CD and see if you have the same issue.

Good Advice I wiil check it BUT

On the live CD I have the Original FC6 Kernel not the updated one! and the problem occured after updating the kernel so i dont think its the BIOS becuase the current BIOS worked well with the ORiginal FC6 Kernel!