As for the printer u dont have to install it again in the laptop by running the installation CD again, all u have to do is to go to your desktop PC in
printers and faxes, locate the HP 2600n right click it and share that printer. Then go to to your laptop and and open printers and faxes and click add a printer click next and remember to select a network or a printer attached to another computer. You can either browser or connect to it, if u no the path to it, the easiest way is to connect to it well i do that for mine. If u want to connect to it in the Name box type this
\\ followed by the computer name where the printer is installed end with
\ that should open your printer just select and continue with the rest. I have the same printer at work and it is simple and easy to connect it. The other method is by connecting through a network but u have to assign it an IP, default gateway or subnetmask.
Hope this works for u.