Give us more information, such as:
What environment do you have (Mac, PC)?
What operating software do you run(Mac Snow Leopard/Lion, Windows XP/7)?
What 'update' are you trying to download (ADE 1.8?)?
What error messages are you getting?
Please visit the below link to troubleshoot Digital Editions installation issue.
If you still have any issues, please reply to me on forums with your system specifications and installation error message.
So that I'll be able to narrow down the issue and fix it as soon as possible.
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