MacBook wifi print through a WinXP /router ?

After installing the HP 4215 All-in-One print driver in a MacBook and hard- wiring it to the printer, it successfully printed.

Now, I can not get it to wifi print over my LAN WinXP network . Other WinXP laptops can wifi print .
The MacBook has been added to the WEP code of the network . It sees the WinXP computers in the workgroup.

LAN set up as :
HP printer model 4215 is hard wired to the Win XP desktop, (so desktop acts as the print server??).
WinXP desktop is hardwired to the Motorola WR850G router .

I' ve read on the internet numerous postings similar to my issue : " network host is busy ; will retry in 30 seconds" .

I read that there was an issue of not accessing due to a series type set up.
Apple support said : "not an Apple problem, call Motorola " .
Motorola support was a tape recording referring to website which did not help.
Anyone with answers out there ? Postings with solutions?