We got a batch of new computers from HP te model is DC7900 and we received a bunch of them
you can see the specs here
The problem with all of this computers is that eventually it looses the connection with the network and it will not repair the connection until you log off the user and then log back in again.
This is a problem specially for computers used in a production environment where the login time due to the number of scurity scripts and general network speed make the log in process very long.
We have 400+ network users in one site and only this model presents this problem.