You should probably avoid Windows Update as possible for the next few weeks. Microsoft was aware of some problems with the new version of 10 -- may or may not have been aware of others -- but the warnings are clear: Stay Away.
One problem concerns an Intel driver. Another problem is that Task Mgr. is broken. The biggest problem is that the upgrade deletes your data, so to be on the safe side, particularly if you can't avoid the upgrade [i.e. are running win10 Home], make sure that you have your stuff backed up somewhere safe.
I've done 6 of the upgrades so far. I just found out about the upgrade deleting data, so I've got to check that out... I don't really store much in folders like Pictures, Video, or Documents, so I've had no reason to look for anything missing, but I do have several apps that store all sorts of templates & such in those folders, so I'll have to mount backups and compare before & after.
I have noticed that many win10 settings are changed after the upgrade, so be sure to check out stuff like your privacy settings, and whether restore points are turned on [it turned all of mine off]. One oddity that I noticed is that after upgrading via the ISO, when I checked for updates [to make sure that adding updates worked during the install] in several cases Windows Update said it was going to install the same upgrade I'd just performed. It then proceeds to go through the steps for an update, preparing to download, downloading, preparing to install etc., but it moved through those steps pretty quickly, & didn't require a restart.
neowin[.]net/news/microsoft-released-the-october-2018-update-with-a-known-task-manager-bug-fix-coming-soon
neowin[.]net/news/some-pcs-unable-to-install-windows-10-october-2018-update-due-to-intel-driver-incompatibility
neowin[.]net/news/windows-10-october-2018-update-issues-highlight-flaws-in-microsofts-seeker-deployment
