Help me i undestand .. false or infect my pc ?

hi, during use my pc normally, why if i try to SCAN COMPLETLY (windows xp) avast 5 at the
end it say: “not infection” , but if i plan a scan at the next power-up …

before the pc start-on ,Avast scan (in temporary modality or in linux mode ?)
it find many and many archive (set-up of program or installer or zip) damage
but the very mistery in this mode… it find many INFECTIONS !

( much Trojan in many programs, i rember in over 10 programs) no a LOG of scan
in this avast scan power-up pc mode???

Now, why this trojan AVAST not find in normal scan operation when use my pc normally,
but it find ONLY in re-start scan mode ???

Is all false postive or not ? but after the scan in this mode it delete this
infections (all trojans) or not ?

I understand it, please help me now ? thanks for your help :slight_smile:

You might get additional help here:
avast!WEBforum | avast! support forums | International zone | Italiano
http://forum.avast.com/index.php?board=26.0

XP Service Pack ???

Could try scanning with superantispyware, just download the free edition and give it a whirl. Worked for me when my av program could not fix.