iTunes on Windows XP Pro - Freezing and no access to iTunes store

I loaded iTunes 10.4 on a Windows XP Pro laptop (3.5 GB RAM, Core 2 Duo) and experienced persistent freezing.  As soon as iTunes would load, the processor usage would immediately increase to 100%, locking up the machine.  The only fix was to slowly open the task manager and end the iTunes process.

No other applications are freezing, the laptop is free of viruses and spyware.

I downgraded to iTunes 9.2.1, which resolved the freezing issue.  However, the iTunes store (signed in or out) will not load.  The loading bar at the top moves to half way and then stops and the iTunes store never loads.  Clicking the home button on the iTunes toolbar does not load the store.

I ran CCleaner and cleaned up any old iTunes entries.  

I have done the following to try and get the store to work:
Ran the Apple Diagnostics task within iTunes, which successfully verified connectivity
reinstalled after deleting the leftover iTunes folder within the Program Files directory
ipconfig/flushdns
reset the hosts file
verified that I can successfully ping itunes.apple.com from the laptop
verified that I can view the iTunes store from a different computer on the same network

Any ideas on how to connect to the iTunes store?