E7500 is bad thing to OC if you have low end mobo (cause its multiplier is 11x) that don't have memory multiplier configs,,,,
you will need FSB around 350 for only 3.85 ghz,,, so if you have low speed ram it will run out of its limit causeing the Oc to fail,,
Actually, that is not quite true. The G41-ES2L supports several different memory multipliers. And low speed RAM? You have that problem no matter what motherboard you use. Because DDR2-800 RAM is virtually standard today, it will give you plenty of OC headroom.
First of all, the E7500, like most Intel chips, has a locked internal multiplier. That's why everything past X11 does not work.
Second, the G31/G41 chipset is an economy, entry level chipset. Unless you get really lucky, you will not be able to push the FSB freq past about 360 MHz. I have a G'byte G41 board. FSB freq of 352 MHz works. 353 MHz doesn't.
This should be your first stop.
Core2 Overclocking Guide (generic guide)http://www.tomshardware.co.uk/forum/259899-11-core-overclocking-guide
Next stop should be a guide for your particular motherboard. Google is your friend.
Go through the guides. Then take your core voltage off Auto and set your memory voltage to factory recommended values. Change the System Memory Multiplier (or whatever your BIOS calls it) from AUTO to 2.00 or the lowest possible value. Then when you increase the FSB, the memory clock will rise in in proportion with it. At an FSB of 266 MHz, your memory clock should be at 533 MHz. Warning: many of the newer G41 boards do not have a 2.0 mem mult.
That G41 board I mentioned up above? I have an E6500 (same basic chip as yours except smaller cache) running at 3.66 GHz (333 X 11) with a mediocre by today's standards ACF7P cooler. It is stable at 3.87 GHz, but the extra performance isn't needed. That same chip runs past 4 GHz in my old EP35-DS3P.