Some machines will not take image

[g8m3rtag]

I am in the Technology Work Experience program at my high school and we use Zenworks imaging to image computers.

Recently though, we have had trouble booting into the imaging program with some of the machines, We turn on PXE boot to LAN in Bios, boot off the network, the w/s pulls an address through the DHCP server, recognizes the DHCP server and everything.

After this it tries to load Zenworks Imaging but then it fails and says Exiting Intel Boot Agent, press any key to continue, then just does a local boot and boots into Windows.

The images we use are stored on the server and on the comptuers that work with imaging we choose restore image, point to the image on the server and it pulls the image onto the hard drive just fine, but half our computers just get that same error mentioned above.

They're Intel motherboards with the 915 chipset.