If you have imported the photos into Lightroom ... as you state above ... then all you have to do is open Lightroom and select a photo and then go to the Develop Module, or press D. You wouldn't need to extract the previews unless you have deleted the photos from your hard disk (and you did not say you deleted the photos from your hard disk)
thanx for the reply. The photos has a little exclamation mark in the top right corner and i have clicked on it and the originals cant be found on my hard disc. So i think it might be deleted. any suggestions...
Wedding photos? Yes you can extract the previews from Lightroom, but they will be smaller than the originals and probably won't print well. You can use this plug-in to extract the previews: robcole.com - PreviewExporter
I think a better idea ... if you have not re-used the camera cards, is to recover the photos there, using software like Recuva - Undelete, Unerase, File and Disk Recovery - Free Download or other similar software.
I think a better idea ... try to recover the photos from your hard disk using Recuva or other similar software
I think a better idea ... you need to develop good backup and file management strategies, so photos are never deleted from the camera card until you have at least two copies on different hard disks. You need to make regular and automated backups of all of your photos and Lightroom catalog. Don't let this happen again.