After trying and failing to force update using the internet disconnection method, I headed over to XDA to look for more answers. I found this guide along with the necessary CAB files to update the Dell Venue Pro to 7.8. It AMAZINGLY worked!
Here’s what you need to do to upgrade your Dell Venue Pro to 7.8 Mine was an AT&T unlocked.
- Be sure that your phone is on Mango (7720) To check, go to settings, About Phone then more info.
- Make sure you have the most recent Zune software installed which is version 4.8
- Download this file: https://dl.dropbox.com/u/15491148/Update%20-%20DVP.zip and follow the instructions on the INSTRUCTIONS.txt file.
- Follow Instructions.txt that says to install Setup-UpdateWP (choose either 64-bit or 32-bit), then to copy each CAB files from each folder to the location where WP7 Update Cab Sender.bat is. Remember to follow numerical order.
- You have to repeat the process 7 times for each CAB folder.
- Play with your new Windows Phone 7.8! don’t forget to thank XDA member cdgoin!