It is possible that a corrupt preference file may cause iTunes to fail at launch with one of these errors:
- The file iTunes Library.itl cannot be read because it was created by a newer version of iTunes.
- The folder “iTunes” is on a locked disk or you do not have write permissions for this folder.
- The iTunes Library.itl cannot be found or created. The default location for this file is in the 'iTunes' folder in the 'Music' folder.
It may be worth trying the shift-start-iTunes method (option on a Mac) to actively select the .itl file that should contain your library. If you still get the error message try Repair security permissions for iTunes for Windows and/or check for interference from anti-virus software.
For more info, see:
Empty/corrupt iTunes library after upgrad… - Apple Community
BTW, are you really using Windows 6 as you tag suggests? If so, that old version may also be causing the problem and you should upgrade.
Another useful resource is the Removing and reinstalling iTunes and other software components section in:
Troubleshooting issues with iTunes for Wi… - Apple Community