Have you tried the basics like cleaning out your Temporary Internet Files, Cookies, and browsing history in IE?
Adobe Digital Editions Error getting License. Current time, then the activation server assumes that the title has expired and you can't download the eBook. Sep 30, 2014 'Unable To Download' error getting license license server communication problem.
Have you tried cleaning out your Temp folder, you can do it by typing %temp% in the Start Menu RUN box. This will open your Temp folder, there you can delete everything that Windows will allow you to do so.
It may be necessary to show Both Hidden and System Files, and also to uncheck 'Hide known file types' in Control Panel/ Folder Options/ View, to navigate to the mentioned Temp location or access (and delete) all the hidden files in there.
You could also reset IE in case it is a problem with your browser or any running Add-ons.
How to use Reset Internet Explorer Settings (RIES)
http://support.microsoft.com/kb/923737#appliesto
http://support.microsoft.com/kb/923737#appliesto
Internet Explorer stops responding, stops working, or restarts [Guided help]:
http://support.microsoft.com/gp/pc_ie_intro:
http://support.microsoft.com/gp/pc_ie_intro:
Tips for solving problems with Internet Explorer
http://windowshelp.microsoft.com/Windows/en-US/Help/8038f9ac-9bf9-4809-8d75-fc42818d8af71033.mspx
http://windowshelp.microsoft.com/Windows/en-US/Help/8038f9ac-9bf9-4809-8d75-fc42818d8af71033.mspx
Can you download from 'Safe Mode with Networking'?
Advanced startup options (including safe mode)
http://windows.microsoft.com/en-US/windows7/Advanced-startup-options-including-safe-mode
http://windows.microsoft.com/en-US/windows7/Advanced-startup-options-including-safe-mode
How to troubleshoot a problem by performing a clean boot in Windows Vista or in Windows 7
http://support.microsoft.com/default.aspx/kb/929135
http://support.microsoft.com/default.aspx/kb/929135
Adobe Digital Editions Unable To Download
Have you tested the problem as a different user in case it is a profile problem?
System Restore might allow you to return to before March if you have sufficient restore points. It would also create an 'Undo' option in case it makes no difference.
How to repair the operating system and how to restore the operating system configuration to an earlier point in time in Windows Vista (or 7)
http://support.microsoft.com/kb/936212/#appliesto
http://support.microsoft.com/kb/936212/#appliesto
How to use the System File Checker tool to troubleshoot missing or corrupted system files on Windows Vista or on Windows 7
http://support.microsoft.com/kb/929833
http://support.microsoft.com/kb/929833