Autosaving changes is good, but they should be saved to an autosave file instead of overwriting the main data files. If I make changes I don’t like, I may not be able to get back to my original version.
Try the Snapshot tool (Under Documents -> Snapshots)
This is indeed something that is different form many programs. I prefer it this way, but I can understand that changing one’s thinking about an auto-save can be difficult.
HOWEVER, that being said. If you are making a change and want to undo it, there is CTRL-Z to undo an immediate change. Or you can use File -> Backup Project To to save your entire project folder in that moment to a file dated when you made it (it will even zip it for you if you like). Then you can go back to previous versions all you like.
This is not a bug, but a stylistic choice from the original developers, perhaps because this was originally a Mac based program instead of a Windows based one.
There are other threads on this question, one of which I’ve been contributing to. I’m a Mac user, but with due respect to you all, I don’t think this is a Mac vs Windows UI issue. As Mightygitis says, it is a design decision by Keith Blount, the originator and master programmer of Scrivener. For many Mac users as well, Scrivener has brought up issues of “This is unintuitive” or whatever. The word-processors that we Mac users have come from work the same way as word-processors on the PC, whether they be Word, OpenOffice or Mac specific apps like Nisus Writer or Mellel. In that we are no different, and there are those among us who have had to get to grips with the fact that Scrivener is not a word-processor, that it needs to work in a different way, and be comfortable with that different way of working.
Those asking for auto-back-up away from the “project file” are thinking of Scrivener as if its file-structure were like Word. If it had that as a file structure, you’d lose all its power in terms of splitting things up, moving things around, including or excluding things from the text without having to delete them or cut and paste them into another document, working in Scrivenings mode on documents that are physically separated in terms of the overall text …
Yes, it’s different from what you’re used to, from what we were used to. Some of us make the transition to the different way of working easily, some of us with difficulty and some have failed to make it completely and have gone (back) to other tools. The real difference is, word-processors do a back-up save to another location when they are programmed to while you’re writing; Scrivener asks you to tell it when you want it to do a back-up save, or you can set to do so on opening and/or closing a project and be happy with that.
That’s not a Mac/Windows UI issue; it’s a fundamental application design issue, and one that gives Scrivener all the power to do what it does.