Sorry my last reply (portuguese) people.
I'm translating it now (at least trying
).
I'm not installing XP over a old instalation.
What I'm doing is to format the partition (C:) where the old was installed.
But I'm not deleting and creating the partitions again.
I have the C: just formated with the XP just installed.
And also have the D: where I place my backups and non-system files (movies, music, projects, etc...)
What happens is that many "entries" of theses f***ing worms was in D: (.exe files only).
I installed avast home on the "fresh installed" XP and run a boot scan on every disks and partitions.
And order to move all ocurrencies to quarantine/chest.
I will run the boot scan again (and also the other you mentioned Tech) to verify if another file was infected between the first and second boot scan.
I think if the second scan return no problems, maybe my PC its clear (that's my real doubt).