(Please note if you are running AVG Internet Security please see the bottom of this post)

First be absolutely certain that you have Java installed on your machine.  In most instances the problem is caused by Java not being installed.  You can install java from http://java.com.  See this FAQ entry for more information on installing Java.

If you’re certain you have Java installed then the problem is most likely the file association.  The Desktop App uses Java Web Start to launch from links on the My Docs Online websites or from the desktop shortcut, using a “.jnlp” file. Some Windows 7 or Windows 8 systems have the file association for .jnlp wrong, specifying that Windows should use Internet Explorer or another program when opening .jnlp files.

To correct this:

• Open the Control Panel
• Select “Associate a file type or protocol with a program”
• After the list of file extensions loads find .jnlp
• If the current default is not shown as “Java(TM) Web Start Launcher” select it and click “Change program…”
• Click “More apps” then “look for another app on this PC”
• Program Files will open. If you have the 64 bit version of Java installed look for “Java”. If not, Go “Up” a folder level and select “Program Files (x86)”
• Open the Java folder, then the most recent folder that starts with “jre”
• Open folder “Bin”
• select “javaws.exe” and click “Open”

NOTE: if your PC is “64-bit” (most newer ones are) but you have the 32 bit version of java (also common) then you will find the right javaws in “program files (x86)” rather than the regular “program files”.

Try the link again.

If this doesn’t solve your problem, and there was a recent Microsoft update done on your system, then there may be a java caching problem, which can be easily solved by following these instructions.

(Please note if you are running AVG Internet Security and having this problem also check this post on using the Desktop App with AVG Internet Security.)