cleaning out a friends system I used a total of 5 different tools, in safe mode, with no network attached, and it took me oh 3-4 hours.
in that time I could have re-formatted his HD, installed WinXP, downloaded SP2, installed all updates, and most all of his programs he had installed....
but I had no way to save the 4+ GB of family pictures, and other data they had.
Life lesson:
Never put anything on your PC for permanent storage. backup backup backup on a removable media or something else that can not be infected.