yes, i did completely de/re-install avast and windows xp plus
service.
it is not possible to see anything on the log because no log
is written after the crash.
other symptoms are:
screen (icons etc…) problems, mouse unusable.
the only way to restart the system is power off/on sequence.

at moment my opinion is that avast ist not the originator of the crash, but each time i start the avast scan program then
i have the problems above…

thank you
pippocavalieri