The System Volume Information folder in Windows 2000 is used to hold information which isn't conventionally accessible in Windows. In Windows XP, for instance, it's used to hold System Restore metadata. (I actually wrote about the Windows XP version of this problem here: http://searchwin2000.techtarget.com/tip/1,289483,sid1_gci991594,00.html.
The best solution would be to boot to Safe Mode and run the virus scanning software from there, or boot to Safe Mode and delete any files reporting as infected by hand. A third alternative would be to use the Recovery Console to do the deletions if Safe Mode doesn't work.
This was first published in August 2004