I work on a PC and have LR 4. I had a hard drive failure. All my photos were backed up and have been put on my computer on a new drive. It is 1.5 TB of photos so I want to make sure I get this right. My old drive shows ? for every file that was on my failed drive. How do I get all the replacement photos into LR and married with their metadata (ratings, keywords, LR edits, etc). I don't know if this matters but I believe I wrote XMP directly into the files for these photos.
Be sure to back up before doing anything. To greatly improve the chances of not losing photos, have a least 3 backups with one off-site.