why dont you just set all your laptops to a static ip? if it works see if it stays then you dont have to worry about it renewing and creating this problem. if something else happens you can narrow down your problem that way.

what OS are they running? laptops and desktops

background/setup info:
so we have a network set up of about 23 computers including our server which is running windows 2003 standard. we have an incredible amount of traffic going to that server due to every workstation viewing and writing data every few seconds. this is an orthodontic office that is completely paperless. charts and personal info are all on one SQL database on one server. i have pictures to manage and everything. but between...