I searched and searched for anything relating to the Dell Vostro 200 PXE boot error "No Network Device Found. Load a Network Module First" If you press Enter you get "Could not Find the Zenworks Installation Source. Activating Manual Setup Program."

I updated my imaging source to Zenworks 7 SP1 Ir3a and still no drivers. I started researching device ids for the Intel E1000 NIC and added some newid entries to the z_zuto.cmd file in the :SYS\TFTP\CMDS folder. I narrowed it to newid="0x8086 0x10c0,e1000"

My file is as follows:
KERNEL boot/linux
APPEND initrd=boot/initrd vga=0x314 install=tftp://$TFTPIP/boot rootimage=/root PROXYADDR=$PROXYADDR TFTPIP=$TFTPIP
splash=silent PXEBOOT=YES mode=2 newid="0x8086 0x10c0,e1000"

You see the newid as the updated portion in bold.

I restarted the workstation and it imaged no problem. Hope this helps.