iTunes Home Sharing Not Working [SOLVED]

Not working and sometimes when it is working, it cuts out in the middle, or when you click on the computer name, the focus goes away from the library.  In other words, really weird.

What it is
iTunes has a feature called "Home Sharing" - it basically allows you to share your entire or part of your library with other instances of iTunes in your home network.  It requires you to login to your iTunes account on both computers.  A typical scenario is to enable Home Sharing on your desktop machine and then access the library from your iPad, Apple TV, iPhone, Mac, etc.

In my case, I have iTunes on my desktop machine running Windows XP in the attic with Home Sharing enabled and then I access the library from my Macbook and Apple TV, depending on what I want.  How to use Home Sharing can be found here.

Symptoms

• Home Sharing machine not showing up in Apple TV or the Macbook
• The Macbook home sharing not showing up on my desktop 
• Home Sharing working intermittently
• Connections getting cut of intermittently
• Usually, restarting iTunes or the desktop computer will make things work.
• Sometimes, restarting the Macbook or the Apple TV will make things work.
• The "working" doesn't last long

The Fix

On the desktop computer where the Home Sharing is enabled, I disabled the "QoS Packet Scheduler" from the network connection:

1. Open Control Panel
2. Open Network Connections
3. Right-Click on your connection (in my case, it was "Wireless Network Connection 4"
4. Select Properties
5. Uncheck "QoS Packet Scheduler"
6. Click OK
7. Restart iTunes if necessary

After doing the above, Home Sharing worked like a charm.