Got to say, if you have a network that a PC struggles to stay visible on, it must be because your network has been designed by a 5 year old.
I've about 15,000 users spread over the whole planet, with a mix of laptops/workstations and thin client systems. No network issues here.
The network isnt the greatest. Its just a gigabit ethernet hub thing and it fails quite often. The PC is the only computer that causes major problems though.