iTunes won't open... says the file 'iTunes Library.itl' cannot be read because it was created by a newer version of iTunes.

I think you are confusing things. There is iTunes the application, which is a piece of software, and then there is your local iTunes database which is stored in the iTunes Library.itl file mentioned in the first post.

If the application needs reinstalling then read on:

For general advice see Troubleshooting issues with iTunes for Windows updates.

The steps in the second box are a guide to removing everything related to iTunes and then rebuilding it which is often a good starting point unless the symptoms indicate a more specific approach. Right-click on the setup file and run the installer as administrator. In some cases you may also need to disable any non-Microsoft anti-virus software while installing.

Review the other boxes and the list of support documents further down the page in case one of them applies.

The further information area has direct links to the current and recent builds in case you have problems downloading, or want to revert to an older version if the current one won't work properly for you at the moment.

Your library and device backups should be unaffected by these steps but there are links to backup and recovery advice should it be needed.

If you had installed, for example, iTunes 12.7 and decided that you didn't want it, and so removed it and reinstalled iTunes 12.6.3 instead then the initial warning message is to be expected as older versions of iTunes cannot read libraries created by newer versions. In such a case you would take an appropriate .itl file from the Previous iTunes Libraries folder inside your main iTunes library folder (usually inside User's Music) copy it up into the iTunes folder and rename the library files so that one takes the place of other. If you have no older .itl files to revert to then delete or rename the one that you do have which allows iTunes to create a new empty library.

tt2

If you're getting that message then iTunes is seemingly installed correctly. Reinstalling iTunes won't make it go away, but if you do need to reinstall see Troubleshooting issues with iTunes for Windows updates.

The section of the first user tip I was trying to direct you to is this:

... 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.

I've assumed up until now that you haven't actually downloaded iTunes, but if you have then you can follow the advice in Empty/corrupt iTunes library after upgrade/crash on replacing the .itl file with one from the Previous iTunes Libraries folder.

tt2

One last time..

When a new version of iTunes comes out it may sometimes make some changes to the structure of the iTunes database. When this happens the current library is copied into the Previous iTunes Libraries folder and used to construct a new version of the database compatible with the new version of iTunes. This doesn't happen with every version update, but if you see this message after installing an older version of iTunes than was previously installed on your computer then the message is to be expected. Either you have an older library you can revert to, in which case do so, or you do not, in which case delete or rename the library file, or actively create a new library somewhere else.

tt2

See Empty/corrupt iTunes library after upgrade/crash. Section near the bottom.

tt2