I have a Dell Inspiron 530s desktop with dual boot, Vista and XP Home. I also have a Compaq laptop operating with Vista that is wireless connected to my DSL modum. The desktop is hadrwired to the same modum. I have a Brother printer connected to the desktop via USB cable. My problem is printing from the laptop while the desktop is operating with XP. Nothing happens, no error messages on ether computer. If I am operating the desktop with Vista, the print command works just fine. I have configured desktop Vista and XP to share this printer. What can I do to get laptop to print through the desktop operating with XP?

use the help program built into windows. query printer sharing and it will give you the details that you need to work this out.

You may have to set up a second printer (in printer control panel) on the laptop. When you set up the printer pointing to the Vista shared printer, it is likely a different network path than when the desktop is running XP.

Another option is to buy a print server that will connect to the dsl modem, eliminating the desktop sharing.
IOGear print server

Boot up the printer system with XP and conduct a fresh installation. because xp sp3 and win vista are forward compatible operating systems, that is why your vista could denies xp some feature, they don not share mush resources with older operating system patches.