Bit of advice, before you wipe any existing working os on the computer.
Find all of the drivers required for the motherboard, such as the chip set sound driver, and mostly important the Ethernet driver for the motherboard.
Download the correct driver bit version depending on what version of windows 7 you intend to install 32bit, or 64 bit windows 7.
Paul.
Burn the drivers to a disk, or put them on a usb flash drive.