Help computer reboots,, no dmp file is created,

Every few days , (could be 4. or 5 days) my computer rebooted by itself and I get a error code 41 kernel power, the system rebooted with properly shuttiong down. A dump file is not bering created. This started in beginning of may. Until then this never happened. This happened when windows is in low use or idle. Microsoft took control of my computer and could not find why it happens Again I am not getting a dump file to check. what can this be.

hard drive tesr--wiith Hdd reginator and check disk no problems
memory test no problem
cpu test by intel softeware diagnostic tool no problem and cpu is cool
test with asus al suitee and cpu temp is 32c and system temp is 31c
virus check with kaspersky and no virus

windows 7 64 bit
malibastes free software
superanitspyware free software
kaspersky internet security
i7 processor, asus motherboard,
2 teribite hard drives,850 corsair watt power supply
h50 cpu cooler, 12 gig 1600 speed balastic memory,
evga gtx460 1gb exhaust ddr 5 memory
creative xfi extreme gaamer sound card

Please provide us with your Event Viewer administrative logs by following these steps:


Click Start Menu
Type eventvwr into Search programs and files (do not hit enter)
Right click eventvwr.exe and click Run as administrator
Expand Custom Views
Click Administrative Events
Right click Administrative Events
Save all Events in Custom View As...
Save them in a folder where you will remember which folder and save as Errors.evtx
Go to where you saved Errors.evtx
Right click Errors.evtx -> send to -> compressed (zipped) folder
Upload the .zip file here.