it could be throtling down if its getting hot, get somthing to monitor your temps like speedfan. if it is too hot it most likly will be your hsf being incorrectly fitted
or maybe your mobo does not recognises your cpu what mobo are you using?? in the bios star screen you should see the name,model and clock speed of your cpu (when you turn on your pc). if it display incorect name or other than your core2 duo is because maybe that mobo dont have core2 duo support
well if u r using a laptop this happens the proc reduces its speed to save power to fix this go to control panel performance and maintenance, power options, and choose home/office and click apply that will fix it
Thanks for answers, I forgot some information, mobo is Asrock Conroe, it supoprts fully Core2, now Iv tested it and if I try to put norml clockspeed 1.87MHz then it reboots again and again, have tryed different bioses and drivers, BIOS test shows everything correctly except now "running at 1400 something MHz" because Iv lowered the clock speed from 266 to 233MHz..well I personally think its the Asrock Motherboard...
in the asrock webpage they have a list of cpu-bios version compatibility so you can flash it with the rigth one!! but that to me is bios problem! it happens with intel cpus lot of mobos says to support many of intel´s latest cpu when they dont.. intul you flash!
asrock isnt a very good mobo there r 3 things in computers u have to stay away from in order: 1 omega power supply 2 pc chips anything 3 asrock mobo u could use any of those 3 for normal desktop pcs that just open word but gaming or encoding? hell no!
Thanks again, but as I said Ive tried newest bios and installed the original back, no affect on these issues.. BTW I think anyway that my computer is now in pretty good shape, windows doesnt crash, I can play oblivion with good details in 20-30fps (nforce 7600 gs) 1280M memory..Allthough OBLIVION crashes but there is nothing new... Hyperthreading works but it pisses me off because first asrock promotes their "safe overclocking" and the cpu supports it too but I cant run it but in 1600 MHz..
BTW again the error message when clockin at normal speed is that "your motherboard is not ACPI complain(all ACPI options disabled), well i sent it and hell of a lot error codes to asrock tech guys so maybe they now whatta do...
acpi stands for, advanced configuration and power interface, which comprises a temperature sensor for sensing an inner temperature of the computer system and for generating an alarm. so realy it sounds like your board is trying not to fry your cpu, which is nice. check in your bios if you can enable it if not complain till they give you a new one.
