Usually it is nothing more than either reversing an update or waiting for the next update in Windows.

...Waiting with a non-functional computer until the next update?... Really?...

While in Linux you'd have to re-import the correct repositories through command line and it might still not work, explain that to your parents.

Why would a non-technical person ever need to use 3rd-party repos? Besides that, "reimporting" a repo is just adding 3-5 lines of text to a file, which can be done via gEdit, or, in most cases, through the settings in a distro's package manager UI.