@kirill1996 maybe because you don't have at least Windows 11, needed to install Opera from version 96?
Or maybe you have downloaded an old offline installer?
The problem was that I could not access the files from under the new account to the Opera folder on the other partition of the drive.
Got full access to the folder and updated offline with the installer with no problem.
Dear Opera team, may I please have any confirmation of the problem along with the estimated resolution time in the "stable" channel?
Also, the problem does not reproduce with the "dev" builds.
Does it have an option to specify command-line arguments for the installer? If so, you can tell it to pass -startmenushortcut=0 --pintotaskbar=0 --desktopshortcut=0 --setdefaultbrowser=0 --run-at-startup=0 (0=false, 1=true, adjust how you like) to the installer.
I would avoid having anything else update Opera though. It's likely to break something. Example.