Need network adapter driver for p5gc-mx a Systemax

Here is a link for your driver. You listed it as Systemax but the P5gc-mx is an Asus motherboard.

Choose the correct operating system and see if these are the drivers.

At the first drop down choose motherboard, at the next drop down choose Socket 775 and at the last drop down choose the P5gc-mx.

Hope this helps.

http://support.asus.com/download/download.aspx