You may receive error code C00D1334, C00D12A7, C101A9CB, or C101000C when you try to use your Zune account to use the Zune software or access the Zune Marketplace. This may occur if the Zune service is down, if your Internet service is down, or if you entered your sign-in information incorrectly.
Close the Zune software, restart your computer, restart the Zune software, and then try to sign in again.
As obvious as it seems, make sure that you're connected to the Internet. You might have lost your Wi-Fi connection, your service might be down, or your router might be offline and need a simple restart. To check your connection on the computer having the problem:
Click Start, and then click Control Panel.
If you’re using Windows 8: From the Start screen, start typing control panel, and then press Enter to access your control panel screen.
Click or tap Network and Internet, and then click or tap View network status and tasks. This screen will tell you whether you're connected to a network or not.
If you're not connected, click or tap Connect to a network from the status window, and then select an available network. If it shows you’re connected to the wrong network, select the correct one and enter your passcode if requested.
If you still can’t connect to the Internet, there could be a problem with your Internet service. You can wait a while and sign in again later, or contact your service provider.
Make sure that you entered the correct email address and password. Here are a few tips to consider when signing into your Zune account:
Make sure the caps lock key on your keyboard is off.
The email and password for your Zune account is the same one you use to sign in to your Xbox account and Microsoft account, which was also called your Windows Live ID.
If you recently added or changed a Microsoft account, and you used an older account to set up your Zune, this new account is not going to sign you in to your Zune account.
If you want your Zune account associated with a new Microsoft account and password, the only way you can do this is to open a new Zune account, which will be separate from the one you already have.
If you forgot your password, or you can’t sign in using the correct password, go to Reset your password.