First and foremost: Forget re-importing. You would loose all your edits. Importing is strictly only for images that have never been imported before.
The remedy for "missing" photos is to re-link them.
In Lr / Grid View right-click the top-most folder in the folders panel. By "top-most" I mean the parent folders of all folders. If you have several parent folder right-click one of them.
Then select <Find Missing Folder>, navigate to the corresponding folder on your new drive E and select it. Do this for every other parent folder. If the folder names and structure haven't changed Lr will find the sub-folders on its own.
For more see here: http://www.computer-darkroom.com/lr2_find_folder/find-folder.htm