Printer Sharing - Lexmark

My configuration before I changed out my wired connection to the Lexmark printer was I had one HP Laptop running Windows XP SP2. I also had a dell laptop connected wirelessly to the router and thus to the home network.

I was easily able to print wirelessly from the DELL laptop by virtue of the above confiuration as long as the HP Laptop was on.

Now, the new scenario is that the HP Laptop is no longer hooked up to the Lexmark printer via the usb cable. Now, the new Dell desktop is hooked up to the lexmark printer via the usb cable.

My HP laptop can see the printer and it actually adds it as its printer. When it goes to print, nothing ever comes out. I have searched on the internet for three days. I have even tried adding a port when adding a local printer to the HP laptop. That doesn't work, it just says it can't communicate with the printer. Lexmark technical support was of no help. They just tell me that my P6250 is not a wireless printer so I can't do what I'm trying to do. Well hello Lexmark, but the Dell Laptop as mentioned in the top paragraph was printing wirlessly by going through the network connection and it was printing just fine to the Lexmark P6250.

Am I just going to have to go buy another newer printer; am I stuck, or is there another solution to make my two laptops not only see the Lexmark P6250 attached to my Dell Desktop running Vista but be able to print successfully.