Spotlight search bar doesn't show up in middle of screen For some reason, when I activate Spotlight, the bar shows up in the top right part of the screen instead of the middle. I've tried restarting and connecting to an external monitor, to no avail.
The Spotlight window remembers its last location. You can drag it back to the original location — it snaps to the X and Y coordinates of the initial position, so you can ensure it is back where it started.

If the Spotlight bar does not remember its last location, make sure ~/Library/Preferences/com.apple.Spotlight.plist is writeable, as this plist file is where the coordinates are stored.