I have 2 identical Dell dual-core PCs running Windows 7 Professional. They both have manual TCP/IP settings running through a router that has DHCP switched off. I have no problem getting files backward and forwards between the machines, and I can easily add the Brother laser printer (which is also a fax) on the 2nd PC (it is attached physically by a USB cable on the first PC). I downloaded the latest "proper" Brother drivers from their website, and went through the whole "proper" Brother install procedure with no errors. Adding the printer on the 2nd PC seems to involve transferring the driver from the 1st, so it looks like the correct driver is being used on both PCs.
However, after booting up each morning, the shared printer is gone from the 2nd PC and requires adding again. I've done some BINGing for a solution, but all the solutions I found related to HP printers HP CUE DeviceDiscovery Service. Neither PC has an HP of any sort attached or previously installed (both PCs were completely reformatted & reloaded when I got them).