Would it be reasonable to ask you to explain better? "CPU runs away and then freezes my machine" (for how long it runs away and how you see it). Why can't you see the processes running in that time (with watch top, for instance) but you can see the cpu running away?. Does the laptop freezes? So, how you see it? Too short time, not conclusive, I think. It happens if you don't run firefox? May be a problem with an add-on? Sorry if you already answer that. <div class="gmail_quote"><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> Thanks Jeff and Liam Jeff, yup when I ran my DELL hardware test I ran everything from fan tests to RAM. So all good there we hope. I'm really not seeing any particular process causing the problem, and also seem to feel that I can't make a convincing argument for hardware being the issue. I suppose my concern is that there's been an update that has somehow buggered things up. But surely Canonical/Ubuntu check this on a laptop they've agreed LTS on? Any other words of wisdom on what next to do? Thanks, Quin -- ubuntu-users mailing list <a href="mailto:ubuntu-users@lists.ubuntu.com">ubuntu-users@lists.ubuntu.com</a> Modify settings or unsubscribe at: <a href="https://lists.ubuntu.com/mailman/listinfo/ubuntu-users" target="_blank">https://lists.ubuntu.com/mailman/listinfo/ubuntu-users</a> </blockquote></div>