Are you tired of seeing the Time Machine Backup message each time you insert a new hard or flash drive into your Mac? There is a quick and easy fix to disable the Time Machine Backup message altogether. This will allow you to insert new flash or hard drives into your Mac and quickly format them how you want without needing to click the Time Machine prompt.
Disable the Time Machine Prompt:
Do you want to use Hard Drive to backup with Time Machine?
Time Machine keeps an up-to-date copy of everything on your Mac. It not only keeps a spare copy of every file, it remembers how your system looked, so you can revisit your Mac as it appeared in the past.
1. Open Terminal Applications -> Utilities -> Terminal
2. Type the following in Terminal and hit return to disable the Time Machine Prompt.
defaults write com.apple.TimeMachine DoNotOfferNewDisksForBackup -bool true
Note: This will not disable Time Machine backup as a service on your Mac. It only disables the window prompt you receive similar to above.
If you decide to enable the Time Machine Prompt again, you can simply enter the following command into Terminal.
defaults write com.apple.TimeMachine DoNotOfferNewDisksForBackup -bool false