iTunes Music Store Connection Problems
One of the most common iTunes Music Store problems is that you simply are unable to connect to the iTunes Store, either consistently or at all. The immediate place to look at when you can't connect to the iTunes Store is your Internet connection as iTunes works the same as any web based service, and an interruption with your service will cause immediate iTunes Music Store problems.
As long as your Internet is functioning correctly then you have a step-by-step process of iTunes troubleshooting to go through. Right off the bat try closing out iTunes and reconnecting as well as restarting your computer completely. You may even want to try to reset your Internet connection by unplugging your router for up to a minute, plugging it back in, and trying over.
First, check the version of iTunes that you are running. If your version of iTunes is significantly out of date then you will need to update it to the newest possible version. Your keychain may be the problem as well, so going through a system of Keychain First Aid is important. This is really only an issue if you are on a Mac computer, and there is built in features to deal with this issue. If you are on a Windows based PC then you will need to make sure that your version of Windows has the most up to date Service Pack, which is a built in update feature in the same way that the Mac OS has its updates presented.
If you still can't connect to the iTunes Store at all then you may be having a problem with your Internet Service Provider where there is an actual hardware component blocking the iTunes connection. Here the iSP needs to be contacted and the issue approached right at the source of the Internet service. This could also be an issue around the Firewall that you are using on your computer. The best way to check this quickly is to turn the Firewall off and then check to see if it still can't connect to the iTunes Store. If it can then you should go into the Firewall's settings to make sure that it will allow for iTunes to connect to the internet.