I have upgraded my iTunes for Windows and I have lost all my apps and music

Question

I have upgraded my iTunes for Windows and I have lost all my apps and music.
Although i signed in with my iTunes account, i can see only 5 apps (that i downloaded in the last 2-3 days), although on my iPad and iPhone i have more than 100 apps.
If i connect my devices to iTunes, the syncronisation will be made the other way, from iTunes to iPhone/iPad, so i will lose everything.
1. How can i restore these apps from the iCloud back-ups from my devices to my iTunes? Or any other method possible?
2. If you can also give me a suggestion about how to find my music playlists, that would save me from a lot of useless work on creating them again.
Thank you!

Answer 1

Empty/corrupt library after upgrade/crash
Hopefully it's not been too long since you last upgraded iTunes, in fact if you get an empty/incomplete library immediately after upgrading then with the following steps you shouldn't lose a thing or need to do any further housekeeping. In the Previous iTunes Libraries folder should be a number of dated iTunes Library files. Take the most recent of these and copy it into the iTunes folder. Rename iTunes Library.itl as iTunes Library (Corrupt).itl and then rename the restored file as iTunes Library.itl. Start iTunes. Should all be good, bar any recent additions to or deletions from your library.
See iTunes Folder Watch for a tool to catch up with any changes since the backup file was created.
In the unlikely event that all the media has been inexplicably and permanently removed from your computer, see Recover your iTunes library from your iPod or iOS device.
When you get it all working make a backup!
tt2