With the release of iTunes 12.1 many people trying to downgrade back to iOS 8.1.2 are finding out the latest version of iTunes has broken the restore process. This simply means that they, or you, are stopped in the process of downgrading to iOS 8.1.2, or any other firmware version, by iTunes. If you want to downgrade iTunes 12.1, or 12.1.1, Back to 12.0.1 follow the step-by-step instructions after the jump.
Step 2. In the Control Panel uninstall Apple Mobile Device Support, Apple Application Support, iCloud and then iTunes 12.1, or 12.1.1.
Step 3. Change the extension on your “iTunes Library.itl” file to “iTunes Library.bak”. you can find this file in C:\Users\YourUSERNAME\Music\iTunes.
Step 4. When you’re done reboot your Windows machine
Step 5. When you computer reboots you’ll now be able to install iTunes 12.0.1.
Step 1. Download Pacifist from Pacifist.com and install it
Step 2. Quit iTunes, remove all its traces using Activity Monitor
Step 3. Download iTunes 12.0.1 for OS X and mount it but don’t install it
Step 4. Launch Pacifist, which you downloaded is earlier
Step 5. Click on Open package > iTunes under Device in the left side bar.
Select Install iTunes and then Open in the bottom right corner
Step 6. Click on Contents of Install iTunes then select Install from the top bar. Follow the on screen instructions until installation begins
Step 7. After a few minutes, you should see a box saying Application already exists. Check Don’t ask again for this installation box and click on Replace
Step 8. Wait for some time until the process is completed
Note: If it still doesn’t work, use the Microsoft Troubleshooter at. Let it run and select the problem with your software. A list of programs will show, select iTunes. The Troubleshooter should move the muscle for you.
Let me know if this worked for you in the comments section down below!