Vista not seeing XP machine

I'm trying to help a friend set up a home network, so all the computers can wirelessly use the printer attached to the new desktop, which happens to run Vista. I've set up another desktop and a laptop - both running XP Pro. I think I set up the workgroup correctly on the Vista machine and on the XP desktop. In fact, the XP Desktop connected to workgroup ok, but can't see the printer and I can't ping the Vista machine from the XP Desktop. BTW, the Vista machine can ping the XP Desktop, but does not see it in the Networks window. I also downloaded and installed the LLTD responder onto the XP Desktop. I haven't even tried anything on the XP Laptop yet. Is this something someone can help me with?? My goal is to enable the XP machines to use the printer. Thanks

Hello,
This is a common problem.
First, did you turn on Network discovery in Vista?

• Click on the start button.
• Select control panel.
• Open Network and sharing center.
• turn on Network discovery and Printer sharing.

If this does not work, try this
Click Start, and then click Network. (Or you can click Start, type ncpa.cpl into the search box, and press ENTER).
2. Click on the Network and Sharing Center, and then click Manage Network Connections.
3. Right click on the Local Area Connection or the connection you are using.
4. Select the Internet Protocol version 4 (TCP/IPv4)
5. Click the Advanced button under the General tab.
6. Click the WINS tab.
7. Click the Enable NetBIOS Over TCP/IP button.
8. Click Ok.