Q. I noticed the hard drive on my Windows PC has a huge amount of space reserved as a "recovery partition." Do I need this if I already run a backup of my files every night on an external drive?
A. The recovery partition is an area of the hard drive created by your computer's manufacturer. The partition can take up several gigabytes of space on the drive, but it is typically where your PC's maker has installed troubleshooting tools, system utility programs and a copy of the operating system in an untouched, right-from-the-factory state. If you do not have another way to restore your computer's copy of Windows without using the recovery partition, you may want to keep it around in case you ever need to reinstall the operating system from scratch.
Depending on the type of backup program you use, you may have copies of your personal files and settings on the external drive, but would need Windows installation DVDs or a disk image of the recovery system to get fully up and running if your hard drive ever encounters serious problems. (Some programs, like Macrium Reflect or Carbonite Mirror Image, do copy the operating system, applications and all the files on the drive to create a complete backup for times when you really need a full recovery from a hardware disaster.)
Check your computer's manual or manufacturer's Web site for information about the recovery options for your model and anything you need to keep in mind about the warranty if you decide to delete the recovery partition. Over the years, companies have changed the recovery tools provided. Instead of a set of Windows CDs or DVDs included with a new computer, the manufacturer may have simply put everything on a recovery partition, including a disc image you can use to restore the PC to its original factory state; some versions of Windows also include tools for creating your own USB recovery drive.
On an older computer that you have personally updated with a newer version of Windows than the one it originally had, the recovery partition and factory-state replacement system is outdated and can be deleted -- just make sure you know where you put those newer Windows discs and have your backup program up to date to restore your personal files.
Managing Sidebar Icons in Mac OS X
Q. I used to have a shortcut link to the Applications folder on the list on the left side of any Mac folder I opened, but it's not there anymore. How can I get that back?
A. The Mac OS X "Sidebar" -- that vertical list of folders, connected devices and shared disks that appears on the left side of open Finder and folder windows -- can be purposely customized or accidentally altered. You can easily put things back to your liking, however.
Click the Finder icon in the Mac's Dock (or on the desktop background), go to the Finder menu and select Preferences. In the Finder Preferences box, click the Sidebar tab to see a list of the default items you can display and turn on the checkbox next to Applications. You can turn off items you do not want to see on the side of your folder windows here as well. Click the Finder Preferences box when you are done.
You can add shortcuts to the files, folders or programs you frequently use by dragging their icons into the Favorites area of the Sidebar; in OS X 10.8, hold down the Mac's Command key while dragging the icon onto the Sidebar. To remove an icon from the Sidebar, hold down the Command key and drag the icon out of the window. You can also rearrange the vertical order of the items in the Favorites area by dragging the icons into new positions in the list.
This article originally appeared in The New York Times.