Every time iTunes starts up it will attempt to open the last library file that it had open unless you press and hold down shift and keep holding until asked to choose or create the library. Currently your active library file is on your desktop and any supporting files that are supposed to go with it will be recreated there if missing.
1. If you haven't already done so I would apply the permissions fix outlined earlier to the folder C:\Users\User\Music\iTunes just to be on the safe side.
2. Open C:\Users\User\Music\iTunes and create a folder called Old. Move any of the following that can be found into the Old folder:
iTunes Library.itl
iTunes Library Extras.itdb
iTunes Library Genius.itdb
iTunes Music Library.xml
sentinel (hidden)
Album Artwork (folder)
and delete any *.tmp files.
3. From the desktop move any of the following that can be found into C:\Users\User\Music\iTunes:
iTunes Library.itl
iTunes Library Extras.itdb
iTunes Library Genius.itdb
iTunes Library.xml (rename as iTunes Music Library.xml, or just delete - iTunes will rebuild)
sentinel (hidden)
Album Artwork (folder)
and delete any *.tmp files.
4. Click the icon to launch iTunes and immediately press and hold down the SHIFT key. Keep holding until asked to choose or create a library. Click choose and browse to C:\Users\User\Music\iTunes\iTunes Library.itl
5. Go to Edit > Preferences > Advanced and correct the media folder location to C:\Users\User\Music\iTunes\iTunes Media. If iTunes prompts to consolidate say No.
6. Check under File > Library > Organize Library... that the Rearrange files... box is greyed out. If not tick the check box and click OK.
7. Run the script Unconsolidated to see if there is anything that isn't where it should be. If there is you can either use File > Library > Organize Library... Consolidate files and then manually clean up the originals, or use my script ConsolidateByMoving which will tidy up as it goes.
tt2