You're not going to be able to get very high on stock voltage. You can go as high as you want until your comp starts crashing programs randomly, won't boot into windows, or won't POST at all. Being able to up the vcore is an absolute necessity. What good is forcing the processor to run faster if you don't supply it with enough juice to get the job done? You should check out the wire mods unless you're a bit hesitant to do that kind of thing (which I know can be somewhat intimidating). I've only done one myself and it was with an old palamino core that wasn't worth it to do anyway.
OK thanks, so there isnt any other way to change my CPU's Voltage without any Motheboard modification? If thats the most I can Overclock to, ah well.
Sorry friend, I think there is no way Although, this does seem to be something that could easily be fixed by a BIOS flash (if ECS ever released a BIOS that allowed vcore manipulation). This is also assuming that the board is physically capable of increasing the voltage. You may want to check around the net and see if you can find a modded BIOS that allows vcore uping. This would also be a big chance in flashing to a modded BIOS, but if it's a popular BIOS there's a good chance all the kinks will be ironed out.
I found a program called CPUMSR (there are no modded bioses for n2u400-a), so it had the abiloty to change the voltage. But when i tried changing the voltage, it didnt do anything and it got frozen on saying Changing Voltage. Any suggestions?
I've never used windows based OCing programs, but the only thing I could think of is that the board has some safe-guard that's preventing you from doing it or, it isn't physically capable of uping the vcore.