How do I backup my files and folders in XP?

Windows XP comes with a backup tool called NTBACKUP (NTBACKUP.MSI from Windows XP CD-ROM). In Windows XP Home Edition, this tool has to be installed manually from the CD-ROM, whereas in Windows XP Professional, this tool is installed by default.
Double-click the Ntbackup.msi file in the following location on the Windows XP Home Edition CD to start a wizard that installs NTBackup: X:\VALUEADD\MSFT\NTBACKUP
X:\ refers to the CD-ROM drive-letter
Note: Usually, OEMs such as Compaq, DELL won't ship the Windows XP CD nor they include the NTBACKUP utility by default. You can download a copy of NTBACKUP.MSI here

Backing up your files using NTBackup Utility:
Click Start, Run and type NTBACKUP
Select Backup tab at the top
In the left pane, scroll to the file/folder which you want to backup and put a checkmark on it.
At the bottom, mention the output filename (the backup output)
Once set, click Start Backup button in the right, and again click Start Backup in resulting dialog

NTBACKUP does not have the ability to write to CDs directly. You will need to save the backup to hard drive, then transfer or burn it to a CD-ROM. Also, while backing up several files, make sure you backup the files in separate sets of each max 650MB (so that it fits on a CD-ROM)
See also FREE Windows Backup Software add-on for NTBackup
Enhanced Windows Backup uses Windows' built in backup engine called Windows Backup (ntbackup.exe) which provides state-of-the-art core backup technology. Enhanced Windows Backup substantially extends the capabilities of NTBackup, providing an effective integrated backup solution.