jhud202 wrote:
Right click on the files on the left side where the question marks are and click the "find the missing photos" line. You will then need to point LR5 to the place on the hard drive where the photos are located. Hopefully, they are all in one folder. You didn't say if you shoot in RAW and put them all in one folder or not, so I am assuming you do.
To avoid going through this again in the future, be sure to make any changes, additions or deletions by using the menus in Lightroom and do not do so directly on the files residing on your hard disc because Lightroom needs to "track" the changes.