The following instructions are for Intel-based Macs, only. Windows will not run on the older processors without expensive and poorly performing software.

One feature of the current Mac OS X software is an applet called Boot Camp that allows you to install and switch back and forth (on restart) between the Apple and Microsoft operating systems.

Section I

1. Power up the Mac under the OS X Leopard 10.4.6 (or higher) operating system.
2. Before installing the new operating system, back up any files and applications installed under OS X.
3. Log in to an administrator account on your computer (if one is set, otherwise continue).
4. Make sure no applications are running.
5. Open a new finder window and access your applications folder.
6. Find the Utilities folder within Applications and locate Boot Camp Assistant.
7. Double-click the application to run.
8. When the application window (aka Wizard, to Microsoft fans) opens, first click the Print button to retrieve a hard copy of the instructions, then click the "Continue" button. This will take you to the next screen.
9. The following screen will read: "Select what you want to do and click Continue."
10. If you haven't already created a Windows partition, select the "create or remove a Windows partition" button.
11. Click Continue
12. Boot Camp Assistant will help you create a new partition for Windows on your internal hard disk (if you have multiple internal hard disks, you can use any). It is extremely important to create a new partition, or you may wipe out your Mac operating system.
13. When you create the Windows partition, you'll have the option of choosing to set aside 32 GB, divide the disk space equally, or set a custom size. The Windows partition must be at least 5GB to accommodate the new operating system. You should also leave at least 5 GB of free space on each partition. Consider which operating system will get more use, and which partition will store more files and applications, then set your size accordingly.
14. When you're satisfied with your choice, click Partition.
15. Following the screen prompts, place your Windows installation disk in the DVD drive. You must use a single full-installation disk (not an upgrade) of Windows XP Service Pack 2 or a more recent version such as Windows Vista Home Basic, Home Premium, Business, Ultimate, or the current incarnation of same. Do not attempt to install an earlier version of Windows.

Section 2

1. At this point, you will select and run the Windows Installation Wizard, following instructions as you would if installing on a standard PC.
2. Install the Boot Camp drivers on your Windows volume by inserting the OS X disk one DVD.
3. If AutoRun opens, quit the program.
4. Using Windows Explorer, locate and select the driver you want to install.
5. Open the driver to start installation.

• Note: You will not be able to use the Eject key on your keyboard while the Welcome screen is displayed (you must be set up and running a user account for this key to work). In order to eject a disk, use Windows Explorer to select the disk, and click the Explorer eject icon.

Section 3

1. If you want your computer to restart automatically after a power failure, click the Boot Camp system tray item and choose the Boot Camp control panel.
2. Click the Power tab.
3. Select "Restart automatically after a power failure."

Windows should now be installed in its own partition on your internal hard drive.

Section 4

To select which start-up disk you want to use for a particular session:

1. Restart your computer while holding down the "Option" key.
2. When the labeled disk icons appear on your screen, release the option key.
3. Use the mouse to select OS X or Windows.
4. Click the arrow under the icon.
5. Your computer will now start under your selected operating system.

Note: You can only use one partition at a time. Although the dormant partition icon will be visible on your desktop, you will not have access to any files or applications under that OS.

If you need to transfer a file between operating systems, you'll have to email it to yourself from the appropriate operating system, burn the file to CD or DVD, or transfer across a network, using a second computer as an intermediary (and yes, Macs and PCs can talk to each other across a network).

Section 5

1. To set the default operating system in Windows, click the Boot Camp system tray item and choose the control panel.
2. Select the disk with the operating system you want to use by default.
3. Restart your computer.

Once the default OS is set, your computer will automatically boot under the selected partition. If you want to use the other operating system for a session, restart while holding down the option key, select the non-default disk, and click the arrow. You will not need to reset your default on restart unless you deliberately want to change it.

Installing Windows on the Intel Mac is usually straightforward and painless; however, if you run into conflicts, consult the instructions you printed in Step 8 of Section 1 for troubleshooting tips. Or ask a teenager to help you.

If you are referring to restarting an iMac, you can choose one of the following options;

1. Click on the Apple menu, and select the Restart option
2. To force a restart, in the even that your iMac freezes, you can hold down Control+Both Command Keys, while holding down this combination press the power button, this will force a restart.

If you are referring to restoring an iMac, you should do the below;

1. You will need your Mac OS X install disk,
2. Insert your install CD/DVD into the drive and restart your computer,
3. While it is booting, hold down the 'D' key for it to run from the disc,
4. Follow the on-screen prompts to do what you wish to do.