Open a project in a new window in IntelliJ after "accidentally" clicking remember decision

Question

It can be changed in in File | Settings/Preferences | Appearance & Behavior | System Settings | Project Opening (or, before version 15, File | Settings/Preferences | General | Project Opening)

In addition to the previous answers by Peter and Trailing Slash, Ctrl-clicking on a project in the "recently opened" list (File > Reopen Project) will open it in a new window - at least on Windows, running IntelliJ 14.0.3 Community edition. Useful if you only want to open a new window from time to time... :)

Unfortunately, this doesn't work with File > Open...

In IDEA 14 and IDEA 15, this can be found in Settings | Appearance & Behavior | System Settings -> Project Opening.

In IntelliJ IDEA 2016.x you can find it by path:

IntelliJ IDEA
  -> Preferences
    -> Appearance & Behavior
      -> System Settings : Project Opening preferences

Answer already there, But I like to give short cut.

1. Press Ctrl + Alt + S.
2. Write 'System Settings' in search box and press enter.
3. Open 'System Settings' in results below.
4. You can see 'Project Opening' there is three options, select which way you want.

   Not only for this for anything, search with word works faster than navigating all the tabs. For example if you want to change font size, search for font. You can see where and all it there.

Note: Some times it searching word not show in search results below. But it will appear if you open tabs in the search result. Like above, if you search 'Project Opening', it not appearing in result below, but it there in 'System Settings'.