 Number 253 - June 2004 |
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| A Third Alternative | |
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by Michael Horowitz, May 2004 The Umbrella, Hampton Roads (VA) Computing Journal | |
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Installing two versions of
Windows on one computer is done by giving each its own dedicated
partition. The old copy of Windows remains where it is, but its
partition will likely have to be shrunk. The new copy of Windows is
installed in a different, new partition. The vast majority of personal
computers have a single partition whose size is the full size of the
hard disk. In this case, this single partition has to be shrunk and a
new partition created in the free space.
This approach is referred to as a multiboot or dual-boot or side-by-side installation. The terms refer to the fact that you can boot (techie speak for "start up") either of two versions of Windows. No version of Windows comes with software that can non-destructively resize a partition. This requires a commercial product, known generically as "partitioning" software. Among such available softwares are Partition Magic from PowerQuest, Partition Commander from V-Communications, Partition Expert from Acronis, and Partition Manager from Paragon Software. There is also a free program, Ranish Partition Manager, but the user interface is said to be very difficult, and for a job like this, it is better to have technical support available. Note that resizing a partition is potentially a dangerous thing. Always back up your most important files first and run a full disk check beforehand. Also, this approach requires more hard disk space than either a clean install or an upgrade install. After all, two separate and independent versions of Windows reside on the computer. Be sure to check the amount of available space on the hard disk before even considering this approach. In general, figure on two gigabytes of disk space. It is also possible to add a second hard disk to a computer and have each hard disk dedicated to one version of Windows. The advantage to this approach is that it can save the cost of partitioning software. In fact, a large enough hard disk can be had for roughly the same price as the partitioning software. The general approach of having different versions of Windows installed in different partitions can be used with any two versions of Windows. The advantages of this are many. You can fall back and use the old OS if the new version of Windows causes trouble. You can migrate to the new version of Windows gradually rather than in big bang. Software and/or hardware that is not supported in the new version of Windows can be run from the old one. Also, the new version of Windows is installed cleanly which means it's less likely to experience problems. The down side is that it requires a reasonable amount of technical skill to set up. However, if the old version or the new version is from the Windows NT family, and there is an available partition for the new version of Windows, then the new version of Windows has some crude, but usable features for managing the two versions of Windows. During installation of the new version of Windows, the old version will be detected. Thereafter, the new version of Windows will offer a list (menu) of Windows instances on the computer at start-up time. You get to choose which copy of Windows to run every time the computer starts up. I am not a big fan of this approach however. For one thing, the description of the older version of Windows is sometimes wrong. Also, files get installed in the partition where the older version of Windows resides. If the time ever comes that you want to get rid of the old version of Windows, it is very difficult. Finally, one copy of Windows sees the files that constitute the other copy - an accident just waiting to happen. A far better approach is keep each copy of Windows totally separate, distinct and unaware of the other copy of Windows. This way, a problem in one copy of Windows cannot affect the other one. Also, each copy of Windows can be reinstalled, removed or upgraded with no effect on the other copy. On their own, the NT-class versions of Windows cannot keep two copies of Windows totally isolated from each other. There are also software programs that manage multiple copies of Windows on a single computer. The most popular such program is System Commander from VCommunications. It offers a list of operating systems that you can chose from each time you start the computer. The software is easier to deal with than the corresponding features in the NTclass versions of Windows. However, multi-boot software such as System Commander costs money and can be confusing to install. Also, it gets in the way of the normal Windows startup process, so if Windows fails to boot, debugging is all the more difficult. I'm not sure if it can keep each copy of Windows totally separate. Total isolation of each copy of Windows requires upfront planning to hide the partition with the old version of Windows. At the time the new version of Windows is installed, the computer thus appears to have an empty hard disk. This worked better with the 9x versions of Windows. Windows 2000 and XP will see the hidden partition at install time, but they can be directed to ignore it both at install time and after the fact. |
You can have total
isolation of each OS, a 100% normal boot process (i.e. no multi-boot
software) and still run either OS. The trick is a program called PQBoot,
included with PartitionMagic, which has to be installed in each copy of
Windows. The computer will always boot to the last used OS. If this is
not the OS you want to run, PQBoot can be run to shut down the current
OS, hide its partition, and boot the other OS. There are DOS and Windows
versions of PQBoot. The DOS version supports command line switches. In
the best case scenario, there can be an icon on the desktop that invokes
the DOS version of PQBoot to shut down the current version of Windows
and start up the other version. Data files can be made visible to each
OS by placing them in a logical partition within an extended partition.
PQBoot makes no changes to logical partitions. Of course, this data
partition has to be formatted with a file system (FAT16, FAT32, NTFS)
supported by both versions of Windows.
Finally, there is yet another totally different approach. Providing the best of all possible worlds, this approach lets you run both the old and the new version of Windows at the same time. This is done using "virtual machine" software. Two companies offer this software for home use, VMware (www.vmware.com) and Connectix (www.connectix.com). They vary in the flavors of Windows they support and in cost. Vmware costs $330, Virtual PC from Connectix is $230. (Connectix was acquired by Microsoft in March 2003.) These products are installed on the current version of Windows (know as the host OS), just like any other software. When you run them initially, you create a Virtual Machine with a virtual hard disk and virtual RAM. You install a new copy of Windows (known as a guest OS) inside the Virtual Machine. Virtual Machines are logically powered on and off, simulating a real computer. Powering a Virtual Machine on/off is somewhat akin to opening and closing a document with a word processing program. There is no limit to the number of Virtual Machines you can define and use other than the hard disk space on your computer. The speed of your CPU and the amount of RAM in your computer limit the number of Virtual Machines that be run concurrently. When a Virtual Machine is running, the interface to it is a normal Windows window, which can be minimized and maximized. The virtual machine is just another running application: You can switch between a virtual machine and other applications in the usual way. VMware offers a full screen mode making it really look like a real computer. VMware and Virtual PC have limitations on the versions of Windows they can be installed onto and the versions of Windows (and Linux) that can be installed in a Virtual Machine. In addition, the guest OS may have limitations that prevent it from running inside a Virtual Machine. Two examples are BIOS locked copies of Windows and the product activation feature of Windows XP. One caution with VMware, the 30 days of technical support starts the day you get the software, whether you install it or not. Note again - these final two approaches require a non-trivial amount of technical expertise. Most likely, the version of Windows you will be installing is XP. Many programs originally written for Windows 95, 98 or Me will not run correctly under XP. For the most part, the burden of researching this falls to you. As for an upgrade install (XP on top of an older version of Windows), the Home Edition of XP can be installed on top of only Windows 98 and Windows Me. The Professional Edition of XP can be installed on NT4 (onlySP6) and 2000. If you are installing XP on top of an older version of Windows, then you can use a program on the Windows XP CDROM called the Upgrade Advisor. It checks for programs and hardware known to be incompatible with Windows XP. You can run it straight from the XP CD. These articles offer some advice specific to XP upgrades: HOW TO Troubleshoot Windows XP - Problems During Installation When You Upgrade from Windows 98 or Windows Me: Last Call for Windows XP Upgrades: - PC World Magazine, May 2002 - Tips on how to do an upgrade installation of Windows XP: Windows XP Professional Upgrade Center - Information from Microsoft on the four steps to upgrading to Windows XP. This article was reprinted from: The Chronicles, August 2003, Palmetto PC Club Michael Horowitz can be reached at: Last but not least alternative, buy a new, hot computer with XP installed! [...Ed] |
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Number 253 - June 2004
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