Windows networking confuses the hell out of me. I can tell you why every single bit is present in the average TCP packet header, I've surveyed hundreds of thousands of time servers on the Internet, I've actually modified the source code for BSD lpd. But I couldn't begin to explain to you how Windows filesharing is supposed to work.
I want to print to Ken's USB printer plugged into his WinXP system. Since removing our wireless ethernet bridge I can see his printer via Windows filesharing. But I doubleclick to install it and Vista demands a printer driver. It claims to have no drivers to choose from. Of course, HP doesn't have a manually installable Vista64 compatible driver for this old printer. I'm screwed.
Turns out there's a solution. Basically you manually set up a new local printer where Vista will let you manually choose from the hundreds of pre-installed printer drivers. Then you fake it out by giving a network name as the port. In detail (from the linked post)