Networking mounts dropping out

I have a network setup with 2 pcs running windows 7 and also the apple tv the problem I am having is that whenever I connect between the 2 pcs or transfer any data from one pc to the other my network mounts in the appletv drop out and the only way to get them back is to restart the pc that has the network drives in, if someone could please tell me an easier way to re mount the drives I would be grateful Thanks.

Are either of the PCs being shut down or put into sleep/standby mode?

No I have that disabled on both pcs as it becomes to annoying.