FAQ: Secrets to Running Multiple Operating Systems

Why limit yourself to one operating system when you can have two (or three) on the same PC (or Mac)?

You don't need separate computers to run different operating systems. Sure, Windows is by far the most common OS running on the millions of PCs in daily use, but that doesn't mean you're stuck using just XP or Vista.

You can add a newer--or older--Windows version to your existing one, and you can choose which one to load from a boot menu when you power on the computer. The latest Macs also offer the ability to dual-boot Mac OS X and Windows via the company's Boot Camp utility. And both Macs and PCs can run popular versions of the GNU/Linux operating system, such as Ubuntu and openSuSE.

(Warning: Creating multiboot configurations often involves using disk-partitioning techniques that can damage or destroy your data. Before adding, removing, or resizing partitions, modifying boot loader software, or altering the master boot record, be sure to back up your files.)

Q. I'm not sure I want to upgrade from Windows XP to Windows Vista. Can I just add Vista to my existing Windows XP installation so I can boot either one?

A. Yes. When you install Windows Vista, choose the Custom install option, and then install to a different partition than your existing Windows XP installation. To delete and create partitions, boot your system with the Vista install disc rather than running the installer within an earlier Windows version; this approach gives you additional options for creating and deleting (but not resizing) partitions. To shrink existing partitions and make room for a new one, use a third-party partitioning program like the free Partition Logic. After you install Windows Vista, the operating system's boot menu will give you the option of booting either Vista or your previous Windows version.

Q. How do I change which operating system boots by default, the delay before booting, and the menu text in the multiboot menus in Windows XP and Windows Vista?

A. In Windows XP, open the Control Panel's System applet, select the Advanced tab, and click Settings under Startup and Recovery. Select the default operating system from the drop-down list in the System Startup section, and select the delay time in the field next to 'Time to display list of operating systems'. Click Edit under System Startup to open the boot.ini configuration file in the Notepad text editor; this editor lets you modify the default text label (enclosed in double quotes) for each operating system in the menu. Windows Vista's boot menu options are nearly identical to those in Windows XP (click the Advanced system settings link in Control Panel's System applet, and then choose the Advanced tab), but Vista lacks the Edit button.

To modify the boot menu listings, open a Command Prompt window as Administrator (choose All Programs, Accessories, right-click Command Prompt, select Run as Administrator), and enter bcdedit. You'll see a list of the current boot menu settings, including separate sections for each operating system listed. To modify the menu text for a listed OS, use the command bcdedit /set identifier description "Menu text", where identifier is the identifier listed in the bcdedit output, and "Menu text" is the new menu text you want to create. For example, to change Windows Vista's default entry for Windows XP from the annoyingly vague 'Earlier Version of Windows' to the more specific 'Windows XP Home Edition', use the command bcdedit /set {ntldr} description "Windows XP Home Edition".

Q. I've decided that my system is better off running Windows XP. How do I remove the Vista partition?

A. Deleting the Windows Vista partition (using either the tools in the recovery console of the Windows XP boot disc or a third-party tool) is only part of the job: Windows Vista's boot loader will remain behind. To restore the Windows XP boot loader, boot the PC with your XP install disc, press R to enter the recovery console, and log on to the Windows Vista partition. Enter the command fixboot to write a new partition boot sector to the Windows XP partition, and then the command fixmbr to write the Windows XP boot loader to the Master Boot Record of the hard disk where the Windows XP partition is located.

Q. I like Vista--how do I remove the XP partition?

A. Deleting the Windows XP partition gets the OS off your hard disk, but not out of Windows Vista's boot menu. To delete Windows XP's entry from Windows Vista's boot menu, first open a command prompt with administrative rights (using the same steps described above for removing Vista); then enter the command bcdedit /delete {ntldr} /f.

Q. Can I add a Linux distribution to my PC without disrupting my existing Windows installation?

A. Absolutely. Novice-friendly Linux distributions such as Ubuntu and OpenSuSE include disk-partitioning software that lets you resize or delete existing partitions to make room for a new partition for your Linux installation. In addition, Linux distributions generally install their own boot managers (the most common one these days is the GNU GRand Unix Bootloader, or GRUB) and automatically add a system's existing Windows boot configuration to the Linux boot loader's menu.

Q. Can I triple-boot Windows XP, Windows Vista, and Linux?

A. Sure. The easy way is to install them one at a time--first XP, then Vista, then Linux. This arrangement yields a chain boot configuration in which the Linux boot loader (usually GRUB) appears first, listing the Linux distribution and Windows Vista. Selecting 'Windows Vista' launches the Vista boot loader, which in turn offers 'Windows Vista' and 'Windows XP' boot options.

Q. Now that OS X runs on Intel processors, can I install it on my PC?

A. Apple supports OS X installations only on Apple hardware, and it has added features to the OS that make installing OS X on non-Apple computers difficult. Nevertheless, several intrepid OS X fans have managed to install both OS X 10.4 (Tiger) and OS X 10.5 (Leopard) on systems with hardware configurations similar to those of Apple's Intel-based computers. If you're willing to buy the compatible hardware and battle through the incompatibilities and workarounds, you might be able to do the same. Start your quest at The OSx86 Project, where Tiger- and Leopard-loving PC users document their successes and failures on the site's OS X-on-Intel wiki. Or you could just buy an iMac.

Q. Can I install Windows Vista to dual-boot with Leopard on my new Mac?

A. Yes. OS X 10.5 (Leopard) includes the final version of the Boot Camp multiboot configuration utility. To start the process, launch Boot Camp Assistant in Leopard's Utilities folder. You'll see an option to print an installation guide before getting started--definitely print it out, but be forewarned that it is 25 pages long. Boot Camp Assistant defaults to creating a new 5GB Windows partition, which is too small for Windows Vista. Two buttons below the partition graphic let you choose whether to divide the hard disk equally between Mac OS X and Windows or to create a 32GB Windows partition. If you aren't concerned about disk space on the Mac side and you don't need more than a few gigabytes of extra space on the Windows side, click 32GB. To maximize your Mac OS storage but still give Windows Vista room to breathe, drag the divider between the two partitions to the left until the Windows partition is roughly 20GB. Then click Partition to continue the installation. The Apple installation guide that you printed out has all the information you'll need to complete the installation, including installing hardware drivers and dual-boot configuration software from the OS X installation DVD.

Q. Can I configure Tiger to boot both OS X and Windows?

A. Not any more. The beta version of Boot Camp, which is no longer available for download, was designed to stop allowing new multiboot configurations after September 30, 2007. Pre-existing OS X 10.4 Boot Camp multiboot configurations continue to work, but you can't create new ones. If the Boot Camp beta is already installed on your Mac, you may be able to add new Windows or Linux partitions by setting the date back to some time before September 30, 2007. In any case, Apple recommends that technique as a way to enable the Boot Camp Assistant in order to uninstall Boot Camp beta after September 30, 2007.

Q. Can I multiboot Leopard and Windows XP?

A. Yes, but Apple warns that you should only install Windows XP SP2, and that attempting to upgrade your original versions to SP2 will fail. Lincoln Spector explains how to create an updated Windows XP SP2 install disc in his Answer Line Q&A, "Slipstreaming Service Pack 2 on an Old Windows XP CD."

Q. How do I select which operating system boots up?

A. You select the default boot OS by using the Startup Disk utility in OS X's Preferences or by using the Boot Camp Control applet in the your Windows installation's Control Panel. Regardless of the default startup OS setting, you can select the OS you want when you power on the computer: Simply hold down the option key until disk icons representing the installed operating systems appear; then select the OS you want to boot with, and click the arrow beneath it to boot it.

Q. Can I use Boot Camp to create a triple-boot configuration with Max OS X, Windows XP or Vista, and Linux?

A. No. Boot Camp Assistant won't allow you to create another partition if it finds that more than one already exist on the hard disk. To triple-boot, you'll need to install and use the free rEFIt boot menu utility, which lets you add more than one other operating system to your Intel-based Apple computer.

Scott Spanbauer is a contributing editor for PC World.

Scott Spanbauer

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