If you want them to all have the same Network ID, you might want to consider using a Class C network range.
In practical terms though, its not really that much of a great idea. A good practice is to partition a network once it reaches 50-60 hosts. Reason for this is that it makes the network load decrease, while also adding security to the overall network. If you stuck 100 Windows machines on the same network, it will be flooded with broadcasts (something Windows machines love to do), hence reduce the available bandwidth and decrease your network performance....
Cheers,
