You need to install a service pack for Windows XP.
Using a graphical user interface
Download the service pack file to a known location, and then navigate to that place on your file system. Double-click the file, select whether to make backups of critical system files before the service pack is installed, and then click Next. The service pack will be applied.
This process can take anywhere from 5 to 20 minutes. You'll be required to restart your machine.
You can also obtain service packs from Windows Update now. See Recipe Recipe 2.13 for instructions on how to get hotfixes and other updates from http://windowsupdate.com.
Using Group Policy
You can use the IntelliMirror software distribution functionality of Group Policy to deploy service packs to Windows XP machines that are members of domains. You will need to install the Administrative Tools pack from the Windows Server 2003 CD on your XP workstation.
The next time Group Policy is refreshed on your client machines, the service pack will be deployed.
Using a command-line interface
Enter the name of the service pack downloadable file on the command line, and press Enter.
If you are using the command line and do not want the service pack installation prompts to appear on your screen, add the /q switch to the command.
Turning on Automatic Updates should also install service packs for you, if you don't want to do it yourself. For more information on this, see Recipe 2.16.
"Deploying Windows XP Service Pack 2 in Enterprise Environments," at http://www.microsoft.com/technet/prodtechnol/winxppro/deploy/sp2entdp.mspx
For advice on any problems that might result from installing Service Pack 2, check out the following article: http://www.windowsdevcenter.com/pub/a/windows/2004/09/28/sp2_woes.html.