The HDD on my G5 desktop is relatively small. Awhile back, I bought a WD external drive (WD #1) to use for Time Machine backups. In the meantime, my photo collection is growing beyond my expectations so I have added a second WD external (WD #2) to store pix and some other odds and ends. 1. Do I need some type of backup software on WD #2 to use it for storage? 2. Can I transfer all my photo-related software, including the Photo Library, to WD #2? 3. I assume that TM (WD #1)will not back up WD #2 so I'll have to find some other backup source. Any suggestions? 4. I saw in an earlier discussion on this forum that it was not wise to use a storage drive as a scratch drive for my photo post-processing software. I don't understand why not, but if so can I use the TM external (WD #1)? Apologies in advance for all the questions.