Introduction: Hacks #85-94

Setting up your PC to be able to boot the operating system of your choice is a great way to conserve space and energy and is of great benefit to those who like to play games that must run under DOS or Windows 9x (and this chapter has a couple of hacks on improving the performance of these operating systems).

With a bit of preplanning and the right software, you can hack your PC to have multiple operating system personalities, including any operating system from DOS to Linux, as well as any and multiple versions of Windows. There is a variety of options for booting different operating systems on the same PC, with or without separate hard drives or partitions. Multibooting is a great solution for those who love DOS-based games that don't work at all under NT, Linux, or 2000 and work only marginally well under XP. You can keep a Windows 98 or Me installation around just for running those games.

With various multiboot techniques, you can allow different operating systems to share a common filesystem or let each operating system maintain its own unique partitions and filesystems. If you want to share files between operating systems, you have to determine which filesystems are common to all of the operating systems you want to use—in most cases that will be nothing more advanced than FAT-32 partitions—and realize that DOS does not support long (256-character) filenames. (For example, a file named MicroSoft.txt will be named MICROS~1.TXT in DOS.) Table 9-1 lists common operating systems and their respective filesystems to help you determine the file compatibility level to suit your needs.

Table 9-1. Operating system versus filesystem compatibility

Operating system	FAT-16	FAT-32	NTFS 1.2 (4.0)	NTFS 3.0 (5.0)	NTFS 3.1 (5.1)	Linux
DOS 6.22	X
Windows NT 4	X		X	w/SP4
Windows 95	X
Windows 95 OSR-2	X	X
Windows 98	X	X
Windows 98SE	X	X
Windows 2000		X	X		X w/SP3+
Windows Me	X	X
Windows XP		X	X	X	X
Windows 2003		X	X	X	X
Linux	X	X	Read-only (with experimental write support)	Read-only (with experimental write support)	Read-only (with experimental write support)	ext2, ext3, reiserfs,jfs, and more

It should be obvious from the data in Table 9-1

If you don't need to share files between operating systems, the choices become a lot easier; each operating system should use the most efficient partition and filesystem it can accommodate. This consideration is especially important if you must work in a native environment with all of the limitations or features of that environment, such as the file security provided by NTFS or the Linux filesystem. Your choices for multibooting in different ways are many.

Windows NT, 2000, XP, and 2003 natively support multiboot and require you to partition accordingly or accept using just the FAT-32 filesystem on a single drive and single partition providing shared, nonsecure file access. This means you will not get the benefits of NTFS filesystem security, and anyone can access the files on your hard drive after booting up with most typical startup diskettes. Linux also provides multiboot capability with the GRUB and LILO utilities.

Several utility-software vendors provide tools to manage different partitions and provide multiboot capabilities—most notable are V-Com (http://www.v-com.com), with their System Commander product, and PowerQuest, recently acquired by Symantec (http://www.symantec.com), with their PartitionMagic and BootMagic products. There is a handful of freeware and shareware software options, such as Smart BootManager (http://btmgr.sourceforge.net/) and Gujin (http://gujin.sourceforge.net/), available as well. With these multi-boot products (except BootMagic), your entire system is at the mercy of third-party software controlling your drive's boot capability rather than native operating system features.

If you're not into dabbling with various bits of software, there is a brute force method of using different operating systems on the same PC system hardware—using swappable hard drive bays. With this method, you have discrete hard drives formatted with the filesystem and loaded with the operating system and software of your choice. If you need to boot DOS to support game playing, simply power down, remove the Windows or Linux drive, plug in the DOS drive, power up, and go. In its simplest form, this method has the distinct disadvantage of not being able to share files between operating systems, but by adding a second hard drive used for data storage, any operating system that can read and write the second drive's filesystem can share files. A less expensive alternative to using a second installed hard drive is to use CD-RW media or a shared network drive on another system to store your files.

An option in between using a boot manager utility and using discrete hard drives is to install multiple hard drives and a boot manager to select which drive your OS of choice at the moment will boot from. Chances are you do not need a large hard drive for DOS-only booting, even for some of the larger game files, so dedicating a 2-4 GB hard drive as the boot manager and DOS drive may be a good choice, reserving a larger and probably faster hard drive for Windows operating systems, Windows applications, and datafiles.

Finally, if you do not want to fiddle with multibooting options, there is VMware (http://www.vmware.com), which is an operating environment that can spawn one or more operating environments or "virtual machines" under Windows NT, 2000, XP, or Linux. You install VMware as you would any other application, run it, and create virtual machine sessions to run DOS, Windows, or Linux in a window within your main operating system. While there are a few limitations as far as access to hardware, different disk partition types, and network resources that go along with a virtual operating system running inside another OS, VMware is pretty darned cool stuff.

In all cases except using discrete plug-in hard drives, VMware, or the PQBoot utility that comes with PartitionMagic, it is likely a few things will change in your system for each OS:

• The boot manager software you choose may modify the boot sector of your first active disk drive so that the boot manager software loads instead of a normal operating system to allow you to select an operating system. Your system can become totally dependent on the boot manager software, which—unless you are using Windows NT, 2000, XP, or GRUB/LILO to manage your boot selections—puts your system at the mercy of a third-party software vendor. If there is a problem with the third-party software, you could lose the ability to boot your system.

• Changing the active partition is no trivial undertaking: while you can change your Active boot partitions with the DOS FDISK program, it is a cumbersome process requiring you to boot to DOS first and you could mistakenly delete partitions. You do have several third-party options, such as PQBoot, for changing partitions, which this chapter explores.

• Each separate Windows installation ignores the software installed for any other operating system. This means you probably will not be able to run an application installed under one operating system from within another. Installing additional operating systems will require that you reconfigure or reinstall your application's software within each separate operating system so each operating system can use the data you may be sharing with other operating systems.

Choosing to set up your PC to use multiple operating systems begs and pleads for you to either back up your data and make sure you have the installation disks for all of your software, or experiment on a spare hard drive or entire PC system where your data is not at risk. Then, if you choose to configure your working PC for multiboot, by all means back up all of your data.

I know, backups are a pain in the butt and take up a lot of time and media, but they can also save your butt.

The quickest and easiest way to back up an entire drive or partition is to use either Symantec's Ghost or Acronis's True Image or any similar drive imaging utility to copy your complete hard drive to another of equal or greater space. You can also back up to a CD or DVD, which can take up a lot of time. With an image of your hard drive saved to another drive, you can get back up and running very quickly by imaging back to your original drive or using the drive you copied your original drive to. Image backups are probably not something you want to do every day, but they are expedient before doing maintenance tasks like messing with partitions and booting.

For all of the fuss, my personal preference is to use swappable hard drive bays and different hard drives for each operating system. Better yet, use separate PC systems for different operating systems and tasks. I do not expect to be doing my email or documentation on a PC set up for playing games under DOS or Windows 9x, and I won't be playing games under Windows 2000.

However, VMware and its ability to let me run multiple, separate operating systems at the same time on one PC is very compelling: I can game with DOS or Windows apps, dabble in Linux, test a piece of software under Windows 98, and fiddle with a mail server under Windows 2000 at the same time on the same PC, while I handle email and web browsing under Windows XP. Amazing!

PC Surgeon General's Warning: repartitioning, formatting, or adding boot management software can cause data loss. PC "patients" who are susceptible, have adverse reactions, or are allergic to having their life's work destroyed are advised to protect their data at all cost, consult a qualified expert, or avoid these procedures altogether.