I think you're misunderstanding Symantec. You wouldn't want to backup your
system state prior to running a virus removal tool.
Here are their instructions:
"System Restore option in Windows Me/XP
Users of Windows Me and Windows XP should temporarily turn off System
Restore. Windows Me/XP uses this feature, which is enabled by default, to
restore the files on your computer in case they become damaged. If a virus,
worm, or Trojan infects a computer, System Restore may back up the virus,
worm, or Trojan on the computer.
Windows prevents outside programs, including antivirus programs, from
modifying System Restore. Therefore, antivirus programs or tools cannot
remove threats in the System Restore folder. As a result, System Restore has
the potential of restoring an infected file on your computer, even after you
have cleaned the infected files from all the other locations.
Also, in some cases, online scanners may detect a threat in the System
Restore folder even though you scanned your computer with an antivirus
program and did not find any infected files."
Don't forget to turn system restore back on AFTER you are certain that you
have removed the virus.
Rocky