Deployment taking too long

We can successfully deploy one machine in 10 minutes, the rest are taking 1 hour + to do. All machines are the same hardware and software, we are using manual deployment and only doing ONE computer at a time.

The computers are Dell Optiplex 360s. We have tried this in two different networks, and two different server machines (the pc that deployment server is on and the image). The images are only 3Gig so it should be fairly quick.

Any suggestions?

Using the latest build and software by the way.