Thanks Logos and YoKenny:
This is actually my dad´s computer, I´m in Spain visiting and I already opened a thread here:http://forum.avast.com/index.php?topic=62671.0
The viruses, 5 !!! that were in it are gone and with Essexboy´s help is now clean, but the reason SP2 is still there is because the computer is not able to download from windows update, the last update was about 18 months ago
According to Essexboy it seems the the edb log is corrupt and The only alternative left now is a repair install
can`t find the cd so since I´m leaving soon I´m tring to leave the computer as secure as it could be without the windows update ...
I installed a few programs and we´ll see....