Hi everybody, I got the hardware back from the HP support. The support confirmed that there has been a hardware bug in the motherboard of the system.
The motherboard has been exchanged. I have now installed Fedora-19-Mate and everything works ok. Hence this is most probably not a Ubuntu or Linux bug. This bug can be closed. By the way: The support by HP has been very helpful allthough the bug appeared in Linux and this is offically not supported Thanks for everybody for the support!!! ** Changed in: xorg (Ubuntu) Status: New => Fix Released ** Summary changed: - ubuntu-13.04-desktop-amd64 freezes at startup + ubuntu-13.04-desktop-amd64 freezes at startup [solved, hardware bug] -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1178026 Title: ubuntu-13.04-desktop-amd64 freezes at startup [solved, hardware bug] To manage notifications about this bug go to: https://bugs.launchpad.net/xorg-server/+bug/1178026/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs