Depending on the way you like to work, you might feel that one backup every hour is too often (or not often enough). To change this, open Terminal (from Applications > Utilities), and type the following (all on one line), then hit the [Enter] key:
sudo defaults write /System/Library/LaunchDaemons/ com.apple.backupd-auto StartInterval -int 3600
Replace 3600 with your desired backup interval in seconds. For example, you could set a two-hourly backup like so:
sudo defaults write /System/Library/LaunchDaemons/ com.apple.backupd-auto StartInterval -int 7200
If you'd rather not use Terminal, TimeMachineEditor (free from http://timesoftware.free.fr/timemachineeditor) has a much friendlier graphical interface, and enables you to set either short backup intervals measured in hours or schedule daily, weekly or monthly backups to take place at specific times. You can also set up combinations of daily, weekly and monthly backups.
The Time Machine icon is usually located in the Dock; if you can't find it there, try your Mac's Applications folder. The first thing you should notice when you launch it is the vertical timescale to the right of the screen. This enables you to navigate back and forth through Time Machine's snapshots of your system using the large arrows near the timescale – you should see your deleted files repopulate the window from past backups. Once you've found the file you're looking for, click the Restore button, and it will be returned to the appropriate place in your current system.
When you want to restore some types of file, your best starting place is the folder or Mac OS X application from which you deleted it. So, if you deleted an email, launch Mail; for a photo launch iPhoto.
Time Machine is integrated with every aspect of Leopard, so when you launch it, those application windows will remain open, allowing you to search for your lost files. The same thing will happen if you navigate to the folder from which you deleted a misplaced file. Alternatively, if you remain in Finder as you launch Time Machine, a new Finder window will open.
Time Machine and Spotlight
As you might expect, Time Machine can work alongside Spotlight, Mac OS X's desktop search technology, in order to make it even easier to find that deleted file. Simply open a new Spotlight window using the default keyboard command (O+ C+[Spacebar]), and add as many search criteria as you need to, both by entering text in the Spotlight field in the top right- hand corner, and by using the + button to add more information, such as the date the item was created.
Note that you can't start up your Mac from a Time Machine backup. Instead, you'll need to use your Leopard installation disc, either by inserting the disc and rebooting while holding down the [C] key on your keyboard, or by double-clicking the Install Mac OS X icon when the disc mounts on the Desktop. If you think your problem might be a faulty startup disk, we'd strongly suggest you at least use the First Aid section of Disk Utility (from the Utilities menu in the Mac OS X installer) to verify and repair the disk. Sometimes, zeroing out the data on the disk will eliminate file system conflicts, and allow you to start afresh.
Once you're satisfied that your startup disk is okay, restore your system by going to Utilities > Restore System from Backup. Use the onscreen instructions to select the Time Machine backup you want to use to resurrect your system.
