Marking as invalid according to last comment, if it happens again please
reopen it an include the following additional information, if you have
not already done so (pay attention to lspci's additional options), as
required by the Ubuntu Kernel Team:
1. Please include the output of the command
I am not sure but this could also be because the CPU was too hot (due to a
buggy BIOS) and so it was unstable in general. I don't understand though why
windows was stable. Anyway, today I updated the BIOS to another one and now the
CPU temperature seems to be okay. And so far no crashes...
