After you are satisfied that an upgrade is worthwhile, you should perform several additional preliminary tasks. The following tasks are suggested, and depend on the current operating system on the computer:

• Back up your data before upgrading, in case something goes wrong during the upgrade. The easiest way to perform the backup is to simply copy the data folders to another disk or computer because the Windows 98/Me backup and restore utilities are not compatible with those in Windows XP.
• Check the availability of BIOS upgrades from the BIOS manufacturer's website. If upgrades are available, you should install them before upgrading your computer. Otherwise, machines with older BIOS versions may not shut down or restart properly. Furthermore, if the computer is not Advanced Configuration and Power Interface (ACPI)-compatible, you may need a BIOS upgrade.
• Turn off power management features so that they do not activate during upgrade. You can do this from the Power Options applet in Control Panel.
• Use an antivirus program that has been updated with the most recent antivirus signatures to scan the computer to ensure that the computer is free of viruses. In addition, use another program such as the Microsoft AntiSpyware Program (http://www.microsoft.com/athome/security/spyware/software/default.mspx; this utility requires Windows 2000 or later) or a third-party tool to scan for and remove malicious software such as spyware, adware, and rootkits. After you have completed this task, remove or disable these programs because antivirus programs can interfere with the upgrade process.
• Ensure that all hardware is listed in the Windows Catalog. You can use Device Manager on a Windows 98/Me/2000 computer or Windows NT Diagnostics on a Windows NT 4.0 computer to print out a list of all hardware components. Also check with hardware manufacturer websites for updated device drivers.
• If you have used programs such as DriveSpace or DoubleSpace to compress partitions on computers running Windows 98 or Windows Me, you should decompress these partitions before upgrading to Windows XP, and then remove the compression utilities. On the other hand, it is not necessary to decompress files or folders on Windows NT or Windows 2000 computers that have been compressed using Windows NT/2000 NTFS compression.
• If the Microsoft Windows Upgrade Advisor tool has identified software applications as being incompatible with Windows XP, upgrade or remove these programs. Software manufacturers may have released upgrade packs or newer versions that enable older programs to work properly with Windows XP, and with Windows XP SP2 in particular. You should note the following items in particular:
  • Older applications that depend on file system filters such as disk tools, disk-quota applications, and certain older antivirus programs should be removed because they cannot work properly on Windows XP.
  • Some older applications may contain drivers that overwrite Windows XP system files. Windows XP forbids such activity because it would damage the Windows installation. You may need to obtain and install migration dynamic link libraries (DLLs) for such software. Contact the software distributor for upgrade packs containing these DLLs.
  • Network client software for other networks cannot be upgraded for use with Windows XP. You need to obtain new versions for this software. An upgrade for Novell's Client32 is included on the Windows XP Professional CD-ROM.
  • Custom power-management tools have been supplanted in Windows XP by Advanced Power Management (APM) and ACPI. You should remove these tools.
  • Custom solutions for PnP-usage with Windows NT should be removed because Windows XP supports full PnP functionality.
  • Other third-party software items such as fault-tolerant disk options, uninterruptible power supply software, and certain network clients and services should be upgraded or removed.
  • It may be possible to run certain older applications in compatibility mode after you have upgraded to Windows XP;
• Ensure that the latest service pack is installed on your computer. In particular, Windows NT 4.0 computers must be running at least SP5 and preferably SP6a.
• Ensure that no unnecessary programs are running when you are ready to begin the upgrade. Access the Task Manager or the Windows 98/Me Close Program dialog box, and close any programs that should not be running.
• Windows XP does not support volume sets or stripe sets created on basic disk volumes in Windows NT 4.0 or Windows 2000. If you are upgrading a Windows NT 4.0 computer that contains volume sets or stripe sets, you should back up their contents and delete them before upgrading. If you are upgrading a Windows 2000 computer, convert the disks containing these volumes to dynamic storage.