Thanks for your reply, I would like to provide more information on the problem, in case people do not understand..
1. Months ago I ran a Windows Experience Index test on Windows 7 and I was getting 5.9 as processor rating, games were not lagging after some time. When I play PES 2011, the game started well, no lagging, then the game starts to lag.
2. I decided to change motherboard as someone told me that the Biostar G31-m7 TE 's North bridge is close to the cpu and that if I want more performance I need to have a mb with the northbridge which is not near it. I changed motherboard myself, installed the processor in it myself. I started the pc and it booted , I was happy. Then I installed some tools from the new MSI G31 TM -P35 motherboard, one of them was Dual Core, I ran it and got to my facebook page to chat with some friends, a few seconds later I heard a siren saying that the temperature of my motherboard is 93 degrees Celcius. At First I wasnt worried as it came from a software installed on windows, then during the motherboard bootup I decided to take a look in the bios and I was stunned to see 95 degrees celcius...
NOTE: The PC never shut down , even at hot temperature and the desktop performance is normal, idk why games lag , maybe my graphics card is getting old but idk why.
thanks for any help you provide me, I would really apreciate it cause I dont want to lose this processor!