Hey there
I had the same problem as many others: After I've been using iTunes for years, it suddenly just didn't work and reinstallation failed because of the "Mobile Device Service"-error. I wasted tons of time searching a solution on the web - but non of the solutions worked for me. After experimenting a lot, I finally found out how you can get iTunes running again. THIS IS THE SOLUTION!!!
1. Uninstall all the Apple Software in the following order:
- iTunes
- Quicktime
- Apple Software Update
- Apple Mobile Device Support
- Bonjour
- Apple Application Support
2. Go to "C:\Program Files" and delete the folders "iTunes", "iPod" and "Bonjour". Then open the folder "Common Files" ("C:\Program Files\Common Files" and delete the "Apple"-Folder. If those folders don't exist, skip this step.
3. Go to "C:\Program Files (x86)" and delete the folders "iTunes", "Bonjour" and "Apple Software Update". Then open the folder "Common Files" ("C:\Program Files (x86)\Common Files") and delete the "Apple" folder. If those folders don't exist, skip this step.
4. Uninstall the "Microsoft Visual C++ 2005 Redistributable"-Software, the "Microsoft Visual C++ 2008 Redistributable" and the "Microsoft .NET Framework X.X". If you don't have this software installed, skip this step.
5. Open CCleaner (or download and install it from https://www.piriform.com/ccleaner/download), run it and then go to its "Registry"-Tab. Use CCleaner to analyse your Registry-Keys and after the scan, click "Fix all selected issues" (and say "Yes" if it wants to do a Registry-Backup first).
6. Go to your desktop and press "Win + R". Then type "%appdata%" to open the folder where all the temporary Program Data is stored ("C:\Users\YOUR NAME\AppData\Roaming"). Delete the whole "Apple Computer"-Folder in order to remove all the remaining Apple-Files on your Computer.
NOTE: This folder can be as large as 50GB!
7. Restart your Computer
8. Download and install the "Microsoft Visual C++ 2005 Redistributable"-Software, the "Microsoft Visual C++ 2008 Redistributable" and the "Microsoft .NET Framework 4.5". If you're using Windows 10, the ".Microsoft .NET Framework" is already included in the operating system.
Here are the download-links for a 32-bit OS: https://www.microsoft.com/en-us/download/details.aspx?id=3387 https://www.microsoft.com/en-us/download/details.aspx?id=29
https://www.microsoft.com/en-us/download/details.aspx?id=30653
And here for a 64-bit OS: https://www.microsoft.com/en-us/download/details.aspx?id=21254
https://www.microsoft.com/en-us/download/details.aspx?id=15336
https://www.microsoft.com/en-us/download/details.aspx?id=30653
9. Restart your Computer
10. Download the latest version of iTunes: http://www.apple.com/itunes/
11. Install iTunes and have fun!
IMPORTANT NOTE: It is possible that the installation still doesn't work. But this time, the services will start and you will get an error message like "Windows Error 193". For specific error cases like this, Apple provides the fitting solution here: If you see Error 7 (Windows error 193) when you try to install iTunes for Windows - Apple Support. With this additional step, I was finally able to install and use iTunes again.
Please let me know if this solution also worked for you!
Kind regards and have a good time =)