What you need to know about multibooting XP Pro on a Win2K Pro system

As most of you know, Microsoft has finally christened the successor to Windows 2000. The result of the long-awaited merger between the Windows NT and Windows 9x OSs, Windows XP (formerly code-named Whistler) is the official name for the desktop version of the new OS. It comes in two flavors: XP Professional and XP Home Edition. (The next versions of the Win2K Server products will ship under the Windows 2002 moniker.) Many of you will want to test XP during its development phase or after its release, which Microsoft plans for October 2001. A good way to become familiar with XP Pro is to configure your existing Win2K Professional system to multiboot XP Pro. Configuring a system to multiboot these two OSs requires some consideration and preparation, as I explain. (To brush up on the basic concepts and procedures for multibooting Win2K and NT, see "Related Articles in Previous Issues." For more information about XP's new features, check out Paul Thurrott's "Windows XP (Whistler) FAQ" at http://www.winsupersite.com/faq/whistler.asp.)

Prepare for Multiboot
Before you dive into configuring your XP Pro and Win2K Pro multibooting system, you should consider a few things. The first matter concerns the use of basic disks versus dynamic disks. As I discuss in "Discover Dynamic Disks," June 2000, Win2K provides a new disk structure (i.e., dynamic disks) that replaces NT's age-old structure (i.e., basic disks) that originated with MS-DOS. Dynamic disks offer several advantages over basic disks, including support for online management, disk reconfiguration, and duplication of crucial data structures across multiple disks. However, dynamic disks don't let you set up multiboot configurations that include OSs other than XP and Win2K. Other OSs (e.g., Windows Me, Win9x, Linux, DOS) can't use volumes (the dynamic disk equivalent of a basic disk partition) that are housed on dynamic disks.

The second thing you should know is that Microsoft recommends installing each OS instance on a separate partition. Multiple installations on the same partition can cause conflicts over control for files and folders such as the Program Files and Documents folder and the Settings folder. Even if you didn't follow this one-OS-per-partition recommendation with earlier multibooting systems, you should heed it for a multiboot configuration that includes XP Pro. Although the potential problems are similar to those for other multiboot configurations, a multiboot system with XP Pro will be running beta or brand-new software. Thus, not only can you expect no help from Microsoft if you get into trouble, but the risks of conflict, corruption, and unsolvable problems are greater.

If you're running a Win2K Pro system and have dedicated most or all your disk space to the Win2K Pro partition, you'll need to add disks or repartition your existing disks to prepare for an XP Pro installation. If you're using dynamic disks, resizing and allocating new volumes is straightforward. However, repartitioning basic disks isn't as easy and is better accomplished with the assistance of third-party software. My favorite disk-partitioning utility is PowerQuest's PartitionMagic 6.0, which is fast and reliable and supports FAT12, FAT16, FAT32, HPFS, NTFS 4.0, NTFS 5.0 (NTFS5), Linux ext2, and Linux swap partitions.

Another important multibooting tip, which applies to XP, Win2K, and NT installations, is to never use the same descriptive computer name for different OS installations (i.e., give the computer a different name in each OS installation that runs on that computer). Because every XP, Win2K, and NT installation represents the computer in its domain as a different account that uses a unique SID, the descriptive names you give to these accounts and SIDs should also be unique.

If you don't follow this advice, nasty repercussions might result, including incorrect or conflicting WINS or DNS registrations and security and resource-access problems. And don't expect technical support from Microsoft if you duplicate a descriptive computer name, because Microsoft recommends different names for different OS installations.

If you're an Encrypting File System (EFS) user and want to access encrypted files from both your XP Pro and Win2K Pro installations, you'll need to join both OSs to the same domain. In addition, make sure that each user account that will log on to both OS installations uses a roaming profile. These configuration steps are needed to ensure that the information necessary for the user to access encrypted data is available to each OS. Alternatively, you can export a user account's file encryption certificate and private key from one installation to the other.

When you're ready to set up the multiboot system, I recommend that you install the newest OS last, if possible. Newer Windows OSs are better at recognizing earlier OS versions and accommodating multiboot configurations that include those versions. In addition, installing OSs in this order helps eliminate a common problem in which an older OS installed on a system running a newer OS overwrites the newer OS's boot sector. So, if you're setting up an XP Pro and Win2K Pro system, install Win2K Pro first, then install XP Pro. For most users, this order seems natural. However, if you're building a new system or rebuilding OSs on a system, keep this recommendation in mind.

Glimpse the Future
The constraints of running XP Pro and Win2K Pro on the same multiboot system require you to think about whether dynamic disks give you the flexibility you need and whether you must repartition your disks or install new disks to accommodate XP Pro. After you answer those questions and prepare yourself with different computer names for each Windows installation, you can slide an XP Pro CD-ROM into your system CD-ROM drive and preview Win2K's future.

Related Articles in Previous Issues
You can obtain the following articles from Windows 2000 Magazine's Web site at http://www.win2000mag.com.

"Multibooting Windows 2000 Systems," Summer 2000, InstantDoc ID 8824
"Discover Dynamic Disks," June 2000, InstantDoc ID 8688
"Mastering Multibooting Madness," July 1999, InstantDoc ID 5548

Windows 2000 Pro, "Better than a Dual-Boot," January 2001, InstantDoc ID 16245