M/B : EPOX 8k9a KT400
VGA : Geforce 4MX 440
Power : normal 300W
RAM : 256 * 2EA (PC2700)
OS : Win XP pro

Geforce4MX 440's default voltage is 1.5V and my M/B set it default 1.5v.

but Health check menu in BIOS shows that AGP is giving 1.6V

I heard that 4X AGP's voltage at Ge4MX440 is default 1.5v

1. is It normal that my M/B is giving 1.6V to AGP ?
2. I wonder my VGA card could endure 1.6V.
3. is it related to my computer freezing, when I boot pc or when I surfing Internet or when I prepare to install new OS

I am tired of shooting my computer freezing.
I appreciate any your reply.

That card will run very safely at 1.6v, they don't run hot to begin with.

Have you flashed the mobo's BIOS to the latest version? Head over to the Epox website and see if there's a BIOS update, and see what that does for you.