Update, I put back the original OS (vista) , and no bsod anymore.
Shame, as windows 7 tool says that it is possible to insall windows 7 on the system... and the packard bell has drivers for windows 7, only thing packard bell said is that they tested it on windows 7 home premium and should be no problem, but they could not assure me the drivers would work with professional version.
I did not know that drivers were OS version specific? hmm
Thanks anyway.