The alert "iTunes could not connect to iPhone because an unknown error occurred (0xE8000025)" may appear when trying to sync your iPhone in iTunes.
Update to iTunes 7.5 or later. You can download the latest iTunes from here or you can open iTunes and choose Help > Check for Updates.
If the issue continues after updating, try the troubleshooting steps in this document.
If you're not able to update, make sure your user account contains only standard ASCII characters.* Characters other than those noted below are not supported.
* Make sure your user account name only contains these characters:
a b c d e f g h i j k l m n o p q r s t u v w x y z
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
0 1 2 3 4 5 6 7 8 9
Note: For best results use a U.S. English version of Windows.
This document will be updated as more information becomes available.
Important: Information about products not manufactured by Apple is provided for information purposes only, and does not constitute Apple's recommendation or endorsement. Please contact the vendor for additional information.