Uninstall/reinstall- external drive

This is not possible.

Logic must be installed on your system HD in the applications folder. You can, however, install Apple Loops or other additional content on an external drive.
By all means, record your audio files to the external drive. I guess you will have pretty much space on your internal HD once you have moved all the user data (iTunes Library, iPhoto Library, Movies, Downloads etc.) to the external. Applications, however, should remain on the internal drive.

Fox

1) I have a feeling that in the past I was accidentally erased

O my god! I hope you weren't! 😉
Well, you can always reinstall the content from the DVD, can't you? Or, if you have time machine, you should be able to recover files from there.

2) I would like to move the Apple loops to my external drive as you have suggested. Is there an easy way to do this.

I never tried it with the basic Loops that come with Garageband / Logic Express, but i have done it with the Jampacks Loops without problems. Here's how to do it:

You could try to move the whole folder where the basic loops are stored: Library/Audio/Apple Loops/Apple/Apple Loops for Garageband.
1. Move this folder (The "Apple Loops for Garageband" or the wholw parent folder "Apple") to the external drive.
2. In Logic, open the external drive in the Finder and drag & drop the new folder over the Loop Browser. This will enter the new Loops location to the Loops index.

Please tell me if this works for you. If it doesn't, just move the folder back to it's original position and re-index the loops. Should be a cakewalk.

Fox