Ok guys, i'm back with some answers!
The FSB is running on 272*14 (base is 200*14, and i can't change the ratio. I've been told it's locked) which gives me my current 3.8Ghz, but as i said, it'll run perfect but it won't REBOOT, i really don't understand why this happening...
My CPU base/normal voltage is about 1.31(...and something), And now it's running on 1.5375 .
I have another option in my bios called "FSB OverVoltage", it have 3 options :
+0.1 / +0.2 / +0.3 . I've choose +0.3 .
I also had to overvoltage the DIMMs (Ram sticks i guess?) +0.4 because if i didn't, the system won't boot at all. Base memory speed is 667Mhz, and now
it's 723Mhz (I had to change the multiplier from 3.33 to 2.66, because if the the ram was running to fast the system won't boot at all again).
As for the temperature,
Idle, the core is running on 40-42 ºC. When i torture tested the CPU and RAM successfully for 6 hours and 40 minutes, the temperature was 60-62 ºC and stable. I've done the test using Stress Prime 2004, and i ran the program twice simultaneously in order to get 100% CPU Usage (PentiumD, remember?).
By the way, It's Pentium D 820.
About the motherboard, wrote it in the beginning.
I use Gigabyte GA-8I945P-G. And yes, it have 945P Express Chipset.
About the graphics card, unfortunately i use 'Gigabyte Geforce 6600'.
BUT I DO intend on buying a new one soon, I think ill go for the 7900 or 7950.
You guys think Thermaltake 420W PSU is not enough?
I really want to solve this really really annoying reboot problem...