I had the same problem. I removed my graphics card and tried the onboard graphics and no more freezing. I installed the correct Nvidia drivers for my graphics card and it now works perfectly. I found this great post on how to install the correct driver for my graphics card.
http://www.binarytides.com/install-nvidia-drivers-ubuntu-14-04/ -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1440210 Title: KWin crashes multiple times a day and often has to be restarted manually. To manage notifications about this bug go to: https://bugs.launchpad.net/kdebase-workspace/+bug/1440210/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
