Printer not showing up.

Hi

I have a HP Photosmart C4380 (Printer and Scanner). It is plugged into my iMac via USB and i can print to it fine from the iMac. However, i have a Windows XP laptop and a MacBook Pro, both of which cannot print.

On the MacBook Pro, i click the + button in Print & Scan preferences, and it appears as a nearby printer as "HP Photosmart C4380 @ Joes iMac", when i click to select it, I get the error message "Setting up HP Photosmart C4380 @ Joes iMac... Unable to download the software from the server at this time". If I try to add it manually, it says "Auto Select" on the driver section, but then fails to find the C4380 driver. If i choose that driver from the list, it still fails to print. From the MacBook Pro, can i choose any generic postscript driver, there are about 20?

Onto the Windows XP laptop. I open the Bonjour printer wizard, and I get "No printers are available". So XP doesnt even recognise any printers nearby.

This is driving me out of my mind. All I want to do is print, im not overly fussed about scanning.

I hope someone can help.

Thanks

Joe