Can anyone tell me which update to download to protect me
from Blaster Worm

Go here for Microsoft's update:

http://download.microsoft.com/downlo...98bcfad8-afbc-
458f-aaee-b7a52a983f01/WindowsXP-KB823980-x86-ENU.exe

and then go here for symantics:

http://securityresponse.symantec.com.../venc/data/w32
..blaster.worm.removal.tool.html