Most likely reason is that the CPU is staying at reduced freq (for longer battery life) and not going to full speed. You can verify this by downloading CPUID CPU-Z and monitor CPU freq while running the Win 7 WEI. You can also try changing the power mode from optium to performance (should be in the control panel under power options.
as long as the cpu is going to full operating freq when need, then as mi1ez indicated - don't sweat it.
Thanks for your help. Some how you are correct. I was using a 90w ac adpter. When I replaced it with 130w ac acadpter
I did the following after that;
1.reset the rating
2. it hangs when submitted to recalculate the index experience rating
3. rebooted the laptop and restrated in safemode
4. shutdown again and restarted in normal mode
Now it is fine. Thanks again.
Another issue when leave it idle for a long time arround 20-30 mins, it hang my laptop.
Trackpad and keyboard not working but I observerd that I can increase or decrease the contrast from keyboard.