Better yet just shift the folder that was moved back where it came from. Deleting & reimporting loses user playlists, ratings, play counts, date added etc.
Music files are normally at <User's Music>\iTunes\iTunes Media\Music\<Artist>\<Album>\## <Name>.<Ext>
Select a track with an exclamation mark, use Ctrl-I to get info, then cancel when asked to try to locate the track. Look on the summary tab for the location that iTunes thinks the file should be. Now take a look around your hard drive(s). Hopefully you can locate the track in question. If a section of your library has simply been moved, or a drive letter has changed, it should be possible to reverse the actions.
Alternatively, as long as you can find a location holding the missing files, then you should be able to use my FindTracks script to reconnect them to iTunes.
If the files are nowhere to be found on your computer, but exist on a device, seeRecover your iTunes library from your iPod or iOS device.
tt2