ITunes won't open, but opens under other users.

Question

I've tried re-installing it and it still doesn't work. I tried it under a guest user and it opened. However, under my administrator user account it fails to open. Any ideas? Oh, also I've tried starting it in Safe Mode or whatever and it still didn't work.

Answer 1

You've tried the isolation steps in this article, now you should try the User-specific troubleshooting suggestions.
User-specific troubleshooting
If your issue only happens in one particular user account, some of the suggestions below may resolve the issue. Before proceeding however, you'll need to make hidden files and folder visible in Windows. Follow steps 1-5 in iTunes for Windows in Windows Vista doesn't open after upgrading.
Remove iTunes Preference files
Some of the files that iTunes uses to store settings and preferences may be unusable and cause issues. iTunes has two folders where preferences are saved. Move one of them to the desktop and test to see if the issue persists. If it does, move it back and remove the second folder. The location for the two preference folders are:
C:\Users\username\AppData\Local\Apple Computer\iTunes
C:\Users\username\AppData\Roaming\Apple Computer\iTunes
Create a new iTunes Library
Hold the Shift key while opening iTunes. You will be prompted to Choose iTunes Library.
Choose Create Library to create a new one. In the following window you will be prompted to select a location to save the new iTunes Library.
Click Save. iTunes will open the newly created library. After closing iTunes, you can always select the original library by using the Shift key when opening iTunes.
Recreate your iTunes Library
If you iTunes library has become unusable, rebuilding it as described in How to recreate your iTunes Library and Playlists may resolve the issue.
Check for content files with issues
Sometimes a certain audio file can cause iTunes to quit unexpectedly or stop responding when it is analyzing gapless playback information. To determine which file(s) may be cause the issue follow the steps below:
Quit iTunes.
Navigate to the iTunes folder:
Windows Vista - C:\users\username\Music\iTunes
Windows 7 - C:\users\username\My Music\iTunes
Move the iTunes Library.itl file to your desktop
Open iTunes. You should not see any content in iTunes.
From the File menu, choose Add Folder to Library.
Navigate to the folder where your music is located. Typically this is
Windows Vista - C:\users\username\Music\iTunes\iTunes Media
Windows 7 - C:\users\username\My Music\iTunes\iTunes Media
Note: This folder may be called iTunes Music if it was created with iTunes 8 or earlier. Choose an artist, album, or single song to add the to the library
Wait for iTunes to successfully add the songs to your library and perform the gapless playback scan.
If successful, continue adding back more songs to your library.
If there is an issue with one of your files, you will notice your issue reappear after you attempt to add it to the library. At this point you should repeat these steps being careful not to add the files that cause the issue to occur.