this is used to start many viruses
C:\WINDOWS\System32\WScript.exe
R3 - Default URLSearchHook is missing
im not very good with logs so I might have missed something but it seems norton let something pass through. Try scanning with housecall
http://housecall.trendmicro.com
A system restore as Trent Steel said might help but if it doesnt turn it off to remove all restore points since many viruses like to hide there becaus AV's cant get them there.