Thank you very much for your follow up.
However it is impossible for me to restore from my Windows 7.
I was not able to backup my iPad and iPod touch so long through old itunes 12.6.2.20 on my PC with different error these several years. Only iTunes data synchronization worked for my old iOS.
I just wanted to keep iOS10.3.3, itunes 12.6.2.20 and Windows7 environment for my useful local 32 bits application. This application is not on App Store anymore.
My PC is also too old to upgrade to Windows10 with the latest version of itunes.
So it seems I may need to leave the above old environment with iCloud service as it is, and on the other hand, I may need to prepare for the latest environment for iOS and iTunes with the latest Windows PC newly…
I got another information from one of iOS9 users on twitter.
It sounds iOS9 or earlier versions were not influenced by this iCloud issue this time.