A colleague has a small office where they are now using Windows 7 x64 computers connected as a workgroup for performing their work, but the shared USB printer is still connected to a computer running Windows XP Professional x86. The printer was supported by Windows 7 which has the necessary in-box drivers for the device. He tried to get one of the Windows 7 computers to print to the shared printer by clicking Start, then Devices and Printers, then Add a Printer, and then Add a network, wireless or Bluetooth printer. The network printer showed up in the Add Printer dialog, but when he tried to install it a message displayed saying that drivers couldn't be found for the device.
Here's how he solved the problem:
1. Plug the USB printer into the Windows 7 computer so it gets recognized. Updated drivers will be downloaded from Windows Update if available, and the printer will be displayed in the Devices and Printers folder.
2. Right-click on the printer in the Devices and Printers folder and select Printer Properties.
3. Select the Ports tab and click Add Port.
4. Select Local Port and click New Port.
5. Type the UNC path to the printer (e.g. \\name_of_XP_machine\share_name)
6. Click OK until all dialogs are closed, then reconnect the printer to the Windows XP computer and try printing to it from the Windows 7 computer.