Disclaimer: These comments are from a frustrated (though longtime) Windows user, not from a genuine IT person. I post them in hopes that someone can confirm or correct them.
(1) As others have noted, you have only 10 days to roll back to a previous version of Windows 10. Some people have been forward-thinking enough to rename the Windows.old folder (where your previous Windows installation is stored) and another hidden folder ($WINDOWS~.BT) so that Windows doesn’t automatically delete these at the end of 10 days. Obviously, this would have to be done within the 10-day period, and it also requires that you have sufficient disk space (which is why Windows deletes them after 10 days). I haven’t tried this, but it makes sense to me. Here’s a link for this workaround (written when the limit was 30 days, not 10 as it is now):
https://win10faq.com/extend-the-30-day-limit-to-go-back-to-your-previous-version-of-windows/
(2) Apart from the standard version roll-back option, you may have longer to uninstall specific updates that have caused problems for you, though this may not help with an update that changes the Windows version. There are several ways to uninstall updates, described here:
I read of instances where someone was able to use the command-line method to uninstall a troublesome update that was no longer displayed in the list of installed updates. I can’t verify that.
N.B.: If the update in question was the version update from 1607 to 1703 and the 10 days had passed, I’d be surprised if you could uninstall that update. That option wasn’t available on my system, but maybe others will have a different experience. In my case, the Windows Update history was reset when the version changed from 1607 (Anniversary) to 1703 (Creators).
(3) And you’re probably aware that moving from version 1607 to version 1703 probably (definitely?) deletes your existing system restore points, which removes that otherwise-attractive option.