Can't connect to Music Store; connection refused

Question

Since updating to the latest version of iTunes (I am using iTunes 6), I have been unable to connect to the Music Store. However, Apple's support page only covers cases where an "unknown error" prevents connection (and, I should note, nothing it suggested helped). I, rather, get the error message
"iTunes could not connect to the Music Store. The network connection was refused.
Make sure your network settings are correct and your network connection is active, then try again."
My network and internet connections are, otherwise, working fine; I know of nothing wrong with the settings. Now, I know, normally a "connection refused" error means you're trying to connect to the wrong port, but as I cannot find any option in iTunes to specify the host name or port number to connect to, presumably this is not the case. Note that this problem only began to occur after updating iTunes. I am baffled, and Apple's support page, as I said, was no help. (Windows Firewall is set not to block iTunes, and I have no other firewall installed.) Suggestions?
  Windows XP  

Answer 1

The iTunes Music Store uses both HTTP Port 80 and 443. Make sure both are open in any firewall, and also make sure that the following domains are exempted in any firewall/filtering software:
phobos.apple.com
phobos.apple.com.edgesuite.net
You might want to completely shut down any firewall temporarily, just to see if that makes a difference. If you can then connect, you know it's a problem with your firewall.
Another possibility is an erroneous entry in the Hosts file. This tip from Mark Holly resolved problem for another poster (please note that I have not tried this fix so I cannot vouch for nor support the suggestion: I provide it only as a suggestion that worked for someone else):
NOTE: this will change a Windows operating system file. This could cause you problems if not done correctly.
Using Windows Explorer navigate to the following folder:
C:\WINDOWS\system32\drivers\etc.
In this folder is file called 'hosts'. Open it using Wordpad.
On the poster's pc there was in this file one long line. At the end of this line was "127.0.0.1 phobos.apple.com:. phobos.apple.com is the web address for the music store. What "127.0.0.1 phobos.apple.com" is doing is telling the pc to look for the web address only on the computer rather than the internet. By remove this section of the line and saving the changes you may then be able to access the music store without any problems.
IMPORTANT: Before making the changes to the hosts file I highly recommend making a backup of it. That way you can restore the original if other problems occur.
Hope this helps.