9.21. Software Update Few operating-system ideas are simpler or better than this one: Whenever Apple improves or fixes some piece Mac OS X or some Apple-branded program, the Software Update program can notify you, download the update, and install it into your system automatically. These updates may include new versions of programs like iPhoto and iMovie; drivers for newly released printers, scanners, cameras, and such; bug fixes and security patches; and so on. Software Update doesn't run rampant through your system software, however. It's quietly respectful. For example, Software Update doesn't download the new software without asking your permission first and explicitly telling you what it plans to install, as shown in Figure 9-15 . Figure 9-15. When Software Update finds an appropriate software morsel, it presents this dialog box that offers to install it automatically. (If you see a smaller version of this dialog box, with no visible list of the new components, click the Details button.) Apple has always created updated and bug-fixing versions of its software components, but they don't do you any good if you don't know about them. You no longer have to scour Mac news Web sites to discover that one of these components has been released and then hunt down the software itself. 9.21.1. Scheduled Check Tab For maximum effortlessness, turn on the "Check for updates" checkbox and then select a frequency from the pop-up menu—daily, weekly, or monthly. If you also turn on "Download important updates in the background," you'll still be notified before anything gets installed, but you won't have to wait for the downloading—the deed will already be done. (If you've had "Check for updates" turned off, you can always click the Check Now button to force Mac OS X to report in to see if new patches are available.) 9.21.2. Installed Updates Tab Software Update also keeps a meticulous log of everything it drops into your system. On this tab, you see them listed, for your reference pleasure. Tip: In your hard drive Library Receipts folder, you'll find a liberal handful of .pkg files that have been downloaded by Software Update.Most of these are nothing more than receipts that help Mac OS X understand which updaters you've already downloaded and installed. They make intriguing reading, but their primary practical use is finding whether or not you've installed, for example, the 10.5.2 update.   . and so on. Software Update doesn't run rampant through your system software, however. It's quietly respectful. For example, Software Update doesn't. Apple-branded program, the Software Update program can notify you, download the update, and install it into your system automatically. These updates may include